62). Slackwater Elimia They're different than the ones found previously. 170). J. Clench and Ruth P. Turner (1956) published a survey of the fauna from the Suwannee River west to the Escambia River. Ph.D. thesis, University of Michigan, i-xii, 1-324. Apex flat with narrow threadlike keel. Physella gyrina aurea 105, 106). (Thompson, 1968). 1979a. Spiral angulation on whorls sharp and prominent in juveniles, usually becoming convex-rounded or smooth on last whorl in adults. Shell usually small to medium (2-25 mm). Fossaria cubensis Newborn young about 4.5 mm in diameter (this can be determined by removing juveniles from brood pouch). Campeloma geniculum Seminole Rams-horn University of Florida Length of shell 2.0-2.4 mm (Fig. Thiarids are ecologically significant because they tend to replace native snails where they are introduced and because of their abundance. Spurwinkia: Morphology, systematics, and ecology of a new genus of North American marshland Hydrobiidae (Mollusca: Gastropoda). Snails in wild populations range in shell color from yellow to brownish-black, and may contain stripes or dimpling. Aperture usually open; occasionally with a horizontal, shelf-like septum closing posterior part (Fig. Outer lip of aperture strongly sinuous in lateral profile (Fig. Work through the questions, each time choosing the characteristic that best matches your snail from the two choices. As a result . Spiral angulation on last whorl obsolete or bluntly rounded and forming a shallow sulcus below shoulder of last whorl. (Thompson, 1968). Viviparus contectoides limi, new name for V. c. compactus Pils. File Campeloma Aperture broadly attached to preceding whorl across parietal wall. Mantle spotted with black, shaded or unmarked; terminal lobe of penis with complex crests that cause it to look like an animals head; flagellum slender, with scattered and discontinuous glands along edge (Figs. Six species are known to occur in Florida. Essentially identical shells occur repeatedly among unrelated genera and subfamilies. The following shells are commonly found on Florida's beaches. B. Wm. 63). Operculum corneas, without pegs on inner or outer surface. Thompson, F. G. & R. Hershler. Campeloma limum (Thompson, 1968). Similarities in appearance among the exotic species can make identification very difficult. Sculpture consisting of incremental striations only. Operculum paleomelanian, with a large sub-centrally located nucleus (Fig. 75, 76). The aquatic snail fauna of the southeastern United States has long been recognized for its richness and diversity. Basal lip of peristome deeply receded. Narrowly umbilicate. Shell coiled to the right, with the aperture on the right side (Figs. In some genera, eggs are deposited above the water in dry clusters on stems, trees, walls, etc. Sculptured with fine incremental striations and a few fine spiral striations (difficult to distinguish except with transmitted light). The giant African land snail is back in Florida after having been declared eradicated twice. 111). Click on the link in the row that best matches your snail. Female shell about 4-6 mm long (Figs. 15, 18). Whorls generally arched. Mantle diffusely pigmented with melanophores (Fig. Mimic Pondsnail Shell usually large, about 12-16 mm long. Nautilus, 19: 34. 57). Knobby Elimia 171-173). 127); superior tubercles on penis arranged in oblique longitudinal series. 174-176). Penis with a single papilla along left margin (Fig. Peristome narrow to broadly ovate. TALLAHASSEE, Fla. (AP) Florida, a state that encourages people to kill non-native iguanas, pythons and lionfish, has a new invasive species to worry about: the horntail snail, which has never . Vertical ribs relatively strong and more widely spaced. Live snails for shell studies should be preserved in 70 percent alcohol. Shell brightly banded and with large, wide and wavey vertical folds; robust, usually 21-25 mm long (Fig. Shell with or without bright bands; with low wavy growth wrinkles; large but not robust, 23-28 mm long. Shell with prominent ribs and spiral chords on all whorls. Indented Duskysnail The snails are tan colored, high and conical, with mature snails about to 1-inch long. 36). By Ker Than for National Geographic News. (Fig. Operculum tightly coiled with four slowly expanding whorls (Figs. A Guide to Florida Bird Species. Miscellaneous Publication of the Museum of Zoology, University of Michigan, 6: 1-213. Shell smooth. Identify your shells using our popular photo guide to southwest Florida shells from Sanibel Island and beyond. Veliger, 45:269-271. One species, C. chinensis malleatus (Reeve, 1863) (Fig. They have been found in extremely high numbers in some crop fields, including corn, cotton, and peanuts, in home gardens, and around farm . 32). A synopsis of the classification of the freshwater Mollusca of North America north of Mexico and a catalogue of the more recently described species with notes. It should be remembered that it is only a key which emphasizes shell characters. Dense Hydrobe Columellar margin of aperture very thick but not reflected over umbilical area (Fig.103). They are beautiful when they are alive because the body of the snail is black with tiny white dots like the milky way galaxy. The giant African snails detected in New Port Richey, Florida are unrelated to the population of giant African snails eradicated from Broward and Miami Dade counties last year. The lightning whelk ( Busycon sinistrum) is one of the larger univalve snails found in Florida waters. Squaremouth Amnicola (Thompson, 1968). Eight species have been proposed. 46). Pewter Physa Henscomb Hydrobe Many North American snail species were described near the turn of the century by Walker (1918). Body whorl angular. Shell with a brownish hue. 1991. The island apple snail is the largest of the known species in Florida with shell sizes up to five inches in length. One to several dark growth-rest varixes usually present on last whorl. The Florida Department . Shell relatively thin. Umbilicus widely perforate, accentuated by a strong circum-umbilical keel. This genus contains three species. (C.B. 90). Umbilicus open. Shell sculptured with very fine, uniformly spaced axial threads (Figs.168-170). These are white, which is the more prized color in. Choctawhatchee Elimia Columellar margin of aperture wide, flat-faced; apex of spire usually erroded; apical whorls, when present, with minute spiral striations; central tooth of radula with basocones located on ridged surface of tooth (Fig. Sexes strongly dimorphic in size, males about half as long as females. 55). Whorls of spire strongly arched or rounded. 72-74). dalli They were created by or for the Florida Department of Environmental Protection, or its predecessor agencies.Amphipod Key, Volumes 1-5 - LeCroy, Sara E. An Illustrated Identification Guide to the Nearshore Marine and Estuarine Amphipoda of Florida:Volume 1 (2000, PDF, 18 MB).Volume Micromenetus brogniartiana 134). Nuclear whorl 0.29-0.33 mm in diameter. It is believed the snail was introduced via the railway cars coming from Mexico. The other three forms, C. limum (Anthony, 1860), C. floridense Call,1866 and C. parthenum Vail, 1979, are exclusively apomictic parthenogens and have been separated on the basis of aperture coloration, embryonic shell coloration, and contour of the outer lip (Vail 1979a). Female ovoviviparous with about 15 large embryos in uterus. Spire of adults without distinct vertical ribs. Size larger, adults 7 mm or more in width. A catalogue of the Viviparidae of North America with notes on the distribution of Viviparus georgianus Lea. (Thompson, 1968). Choctaw Lioplax Elimia athearni Additional genera occur in the Orient, Southeast Asia, Africa, and South America. Fawn Melania An investigation by FDACS Division of Plant Industry found multiple positive sites with the snail in Miami-Dade County. Apex about 0.4-0.5 times length of shell. Adults with six teeth in aperture, two on the parietal wall and four on the palatal wall. Apex of shell slightly convex in outline. Length of shell 2.0-2.4 mm (Fig. 64). (Jay, 1839). 86). Suwannee Hydrobe North American freshwater snails: species list, ranges and illustrations. Basch, P.F. Peninsula Ancylid Shell larger, 2.8-4.6 mm long; adults with 4.0-4.9 whorls; spire longer, 0.9-1.3 times height of aperture; superior tubercles not arranged in oblique longitudinal series. Malacological Review, 12: 41-49. Identification. The focus on most investigations was on rivers north of Florida, and little attention was given to the Florida fauna. Shell larger, thicker, and opaque; spire 0.9-1.3 times length of aperture; with more than 4.2 whorls; penis flagellum with glandular crests. Shell medium-sized, 2.8 3.5 mm long; spire 0.9 1.1 times length of aperture; shell with 4.2-4.7 whorls (Fig. 22). (Thompson, 1968). Shell sculptured with prominent nodes overlapping suture and forming crenulations. Parietal margin of operculum slightly convex in outline (Fig. 92). Walkerana, 1: 81-365. There were no references to cover the entire state. 1965. Lobe and flagellum with various patterns of dermal glands (Fig. (Thompson, 2000). Few of the North American species have been studied to the extent that their taxonomy, geographic distributions, life histories, and ecology are documented. The reappearance of an invasive snail species forced state officials to enact a quarantine order two weeks ago for residents of Florida's Pasco County, an area north of Tampa along the gulf. Conical Siltsnail Blackwater Ancylid The coloring makes state officials. POMATIOPSIDAE Floridobia ponderosa The primary differences between the two families are based on soft anatomy. Rhapinema dacryon 199). Freshwater snails (Mollusca: Gastropoda) of North America. Outer lip straightened just below shoulder; straightened portion lying at an angle to axis of shell (Figs. Adult shells small, less than 3 mm high; umbilicus closed by the reflected columellar lip; columellar margin of the aperture nearly straight, barely convex (Fig. The VIVIPARINAE is widely distributed throughout Europe, Asia and eastern North America. Shell sculptured with fine spiral threads. Embryonic shell with a strong peripheral spiral chord that continues onto following whorls (Fig. Adult shells about 40 70 mm high (Fig. (Thompson, 1968). Biochemical studies show that in Elimia shell characters are conservative indicators of genetic divergence (Mihalcik & Thompson, 2002). Apical whorls depressed; body whorl obtusely angular above and sharply carinated around funnel-shaped umbilicus. Penny Sprite) Micromenetus floridensis (Baker, 1945). Alexander Siltsnail Shell olive-green with vertical reddish flames and spots. Size small I I to medium, 8-12 mm in length. (Thompson, 1968). Helisoma anceps anceps 201, 207). Plane of aperture nearly vertical when viewed from the side. 169, 172). Aperture strongly oblique. Adult shells about 40-60 mm high (Fig. Overshadowing this genetic divergence are frequent examples of convergent evolution of similar adult shell characters among distantly related species. The family contains many genera and numerous species in South America, Central America, Mexico, Africa, and Southeast Asia. It has many colorful stripes, colors, and bands on its shell which are usually orange, light orange, dark orange, or yellow. Marginal teeth of radula trapezoidal with well-differentiated cusps. Prominent minor spiral sculpture along periphery. Columellart margin of aperture not flat-faced; apex of shell usually entire; penis with large terminal lobe on left side and small appendage-like flagellum on right margin (Fig. Whorls of spire pointed and scalariform (steplike with nearly flat shoulders and deep sutures). Common name: Florida applesnail Taxonomy: available through Identification: This species is the largest freshwater gastropod native to North America (Burch 1982). Clench, W.J. It is important to save some specimens for anatomical studies. The reader will discover how very little we know about any genus occurring in Florida. Length of shell 2.1-2.8 mm (Fig. 47). The radula is then thoroughly rinsed in distilled water, stained, and mounted on a microscope slide. Two-ridged Rams-horn It also was the first adequately illustrated faunal summary published on the Southeast. They are commonly found on live aquatic plant stems, dead leaves and sticks, and on bottles and cans. Shell conical with strongly arched whorls and a deeply impressed suture. Only three widely distributed species occur in Florida. Spire shorter, conical, 0.7-1.3 times length of aperture, nearly straight-sided in outline, suture of whorls weakly or moderately impressed. This is particularly so in the Pulmonata. Aperture comma-shaped, tightly appressed against preceding whorl. (Couper, 1844). Whorls flat-sided with suture weakly impressed. Spilochlamys gravis Umbilical perforation narrow, 1/8 1/10 diameter of shell. (Thompson & Hershler, 1991). They are most common on tropical islands but occur also in cold regions, where they hibernate. Choctawhatchee Pebblesnail) Somatogyrus sp. Hebetancylus excentricus Subspecies bear the same name as the nominate subspecies, as is consistent with the standard used by the American Fisheries Society for fishes, and by other societies for other classes of animals. The genus Viviparus (Viviparidae) in North America. 85). Spiral sculpture faint or absent (Figs. Amber to milky white in color (Figs. CLICK ON EACH PHOTO Fallen Angel Wing -Atlantic Mud Piddock Boring Angel Wing- Striate Piddock Rice Olive After the snails have been in the fixative for a few minutes to several hours, depending upon their sizes, they should be rinsed in water and transferred to 70 percent ethyl alcohol. 95). Shell conical to ovate-conical. Shell usually planispiral, but two species may have a flat-topped, elevated spire. (Say, 1825). You can also navigate through the images by clicking on the arrows near the left and right edges of the enlarged view. Walker, B. (Haldeman, 1841). One species occurs naturally in Florida, and three others have been introduced. The most recent sighting of a giant African land snail took place in 2017, meaning the species can now be considered eradicated in the state of Florida. In 1976 in the St. Johns River 1 found Melanoides tuberculatus with population densities of 10,000/m2. Never preserve shell specimens in formalin. 87). The spire differs between bumpy and smooth but it is always elongated. Rails, gallinules, coots and cranes. It is troublesome mostly in southern Florida as far north as Tampa, but because potted plants are regularly moved northward it can appear almost anywhere. (Vanatta, 1935). Most have monotonously simple, conical or depressed-conical shells that are nearly devoid of taxonomically useful characteristics. Sexes not conspicuously dimorphic in size. Florida Press, Gainesville: i-xv, 1-68; pls. Types of Shells In Florida: Seashell Identification Guide It lurks nearly a foot beneath the dunes of Sanibel Island. Adams, 1841). Adults about 2-3 mm long (Figs. 159). Columellar margin of aperture wide, rounded in front like a spindle. Moderately large, thick-shelled operculate snails. Click on the link in the row that best matches your snail. Cymbal Ancylid Spire long, 1.3-1.7 times length of aperture, convex in outline; shell relatively large and nearly cylindrical; 4.0-4.9 mm long; whorls 5.0-5.7, strongly rounded with a deeply impressed suture (Fig. 7-9). 15). Identifications are difficult in many instances without properly preserved specimens. Wekiwa Hydrobe 44). It is most common in Southwest Florida, and northwest Florida. Stately Elimia 1934. Review of the Planorbidae of Florida with notes on other members of the family. The species made a return in 2011 and eradication efforts took another ten years. 34); penis frlattened, blade-like (Fig. (Walker, 1905). Shell unicolor, with distinct vertical sculpture in addition to strong spiral sculpture. (Pilsbry, 1889). In parthenogenetic organisms each population is inbred in the strictest genetic sense, and frequently a population will have minor characteristics that distinguish it from others. Shell minute, 2.4-2.7 mm long; adults with 3.9-4.2 whorls; spire short, 0.8- 1.1 times height of aperture (Fig. Some hydrobiid snails from Georgia and Florida. Outer lip of aperture arched forward (Figs. The LIOPLACINAE is endemic and include Campeloma, Lioplax, and Tulotoma. Females with an egg-laying groove or sinus on right side of foot; eggs deposited on substrate. The bodies of large snails, such as viviparids and pilids, should be pulled from the shell. 140-146). Shell small, about 3.0-3.5 mm long; adult with 4.4-4.8 whorl; lower corner of aperture tending to be angulate with fluted channel (Fig. Shell elongate with pointed conical spire. (Thompson, 1968). Vernacular names are given only for species. Aperture elliptical and loosely attached to or slightly separated from preceding whorl; 4.5-4.9 whorls. (Fig.114). Adults about 15-18 mm wide with about 5.5 whorls (Figs.183-185). After the shells are thoroughly rinsed, they can be air-dried in cardboard trays. Goodrich, C. 1942. In view of the inconsistency of these shell characters, these three forms may represent only a single species, Campeloma limum, which is widely distributed from the Escambia River system of Florida and Alabama east and north into North Carolina and Virginia. 159, 162, 165). Shell with 3-4 whorls. Jan. 28, 2020 . . Penis simple, elongate-conical, without papillae (Fig. Aphaostracon asthenes 1969. 69). Length of shell 2.2-2.6 mm (Fig. Female oviparous, never with embryos in uterus. Philadelphia, 134: 143-77. With the exception of Liguus fasciatus, these snails have shells that vary in color from ivory to tan, often with brown markings.Liguus shells are brilliantly colored and are frequently marked with yellow, green, pink, and brown. Umbilicus variable. Bantam Hydrobe Now officially known as simply a Snail Kite, the subspecies from Florida and Cuba (Rostrhamus sociabilis plumbeus) formerly known as the Everglade Snail Kite was listed as endangered in 1967.The range of the Florida population of Snail Kites is restricted to watersheds in the central and . Waccasassa Elimia 89, 90). 141). Whorls rounded, not carinate above; occasionally angular below. 132). Malacological Review, 12: 87-88. Inferior crest usually present. Apex of shell flat-topped, but sunken below periphery of last whorl. Transparent white (Fig. 17, 29-32), shell usually banded in Florida forms. Typically, land snails live on or near the ground, feed on decaying plant matter, and lay their eggs in the soil. Introduction to the Physidae (Gastropoda, Hydophila): biogeograhy, classification, morphology. Dusky Ancylid 38). A giant African land snail, photographed at a lab in 2014. Choctaw Lioplax Seminole Siltsnail The horntail . Shell sculptured with fine spiral striations, and in some cases curved axial ribs. Shell usually corpulent, brown or green, generally opaque, but occasionally translucent in juveniles. Penis with 3-7 papillae along right margin and a projection with 1-4 papillae near end on left side (Figs. Penis with some superior tubercles fused into a U-shaped crest; parapical crest raised on a fleshy pedicel; accessory crest and inferior crest usually present (Fig. The shell characters given above for separating the families apply only to Florida species. Contents 1 Shell description 2 Distribution 3 Ecology 4 References 5 Further reading Shell description [ edit] Five views of a shell of Pomacea paludosa Smooth-ribbed Hydrobe 35). Planorbid snails are restricted to fresh water and occur worldwide, being found on all continental landmasses and many oceanic islands. 148). MIAMI-DADE, Fla. As if 2020 did not have enough surprises and curveballs, an invasive snail located in the U.S. for the first time was discovered in-- you guessed it, Florida. Shell elongate-conical, with about 5-7 whorls. Hello Bruce. Penis with large a terminal lobe on the left side and a smaller appendix-like flagellum on the right side. 36); males with a copulatory appendage, a penis (Fig. Aperture elliptical and usually attached to preceding whorl; 4.1-4.5 whorls present. (This character separates only the genera under consideration; genera from other areas of the world do not conform to this distinction.) There have been introductions of this species into Argentina, the Atlantic Islands, Australia, Chile, Haiti, Mexico, New Zealand, and . Most freshwater hydrobiids in the eastern United States are annual species. 70). Giant African Land Snail Identification Sheet - Florida Commissioner of . Spire depressed, much less than height of aperture, occasionally planular (Figs. Females ovoviviparous or oviparous. Wekiwa Siltsnail Fenney Spring Hydrobe Important diagnostic characteristics for subfamilies, genera, and species are found in the female reproductive system, the male reproductive organ (the penis), and modifications of the radular teeth. Vertical sculpture reduced to irregularly spaced and uneven growth striations or low undulating ribs. Tadpole Physa Amnicola dalli. The molluscan family Planorbidae. Newborn shells brown. (Mihalcik & Thompson, 2002). Texture dull. (Lamark, 1822). Recent studies treat amnicolids as a separate families. Papilla with a duct that leads to a blind caecum in nape of snail. Littoridinops is found most frequently in brackish water, although the three species found in Florida also occur in frehswater. Umbilicus closed. Suture simple, not crenulated. (Fig. 68); lobe and flagellum with various patterns of dermal glands; central tooth of radula with basocones located on reflected margin of tooth (Fig. Umbilicus of shell closed. Earlier whorls of adult shell with vertical ribs and spiral chords. Suture deeply impressed, forming a channel. Pseudosuccinea columella Parietal margin of operculum convex. Most other genera have received relatively minor attention, and their systematics are in flux. Shell more slender, about 0.30-0.35 times as wide as high. Adult shell about 4-5 mm high; umbilicus wide; columellar margin of the aperture concave in outline (Fig. Sides of spire straight-sided in outline. 101). The lymnaeid fauna of the southeast is particularly depauperate compared to more northern and western regions of the continent. Pomacea paludosa This family includes four North American genera, Amnicola, Dasyscia, Colligyrus and Lyogyrus, and the European genus Marstoniopsis and some Asian genera. Escambia Elimia The number of whorls persent on the shell can help you easily identify the snail species. (Thompson, 1968). Shell medium to large (12-75 mm). Operculum paucispiral, with about three rapidly expanding whorls (Fig. 1918. Size: 2-4 cm. Elimia buffyae Since then a great amount of fieldwork has taken place throughout Florida, and many additions to the fauna have come to light. 61). Slender Walker Whorls uniformly rounded, not flattened above (Fig.144). It is presented in the form of key supplements with illustrations and habitat information to facilitate identifications. Shell specimens should be cleaned and air-dried. 117). Marisa cornuaurietus Thin and translucent or transparent. Floridobia is known from peninsular Florida north along the Atlantic seaboard to Maine. Adults about 6-8 mm wide (Figs. 169). Body whorl rounded (Fig. Incremental striations uniformly weak. Apex behind center of shell. In Pasco County Florida, a quarantine order was issued for people after the re-discovery of the giant African land snail, an invasive species that can harm to humans, structures, and wildlife. This is essential in the case of the Hydrobiidae. Whorls of spire weakly scalariform, causing the suture to be deeply incised. Spilochlamys conica 99). This species is a fast and voracious predator, hunting and eating other snails and slugs. Shaggy Ghostsnail Floridobia wekiwae They achieve their greatest diversity in genera and species in temperate North America. Peristome ovate to subcircular. Shell larger, 2.2-4.8 mm long. (Conrad, 1834). There is no consensus in systematic biology about how to treat these forms. This snail was twice established in southeastern Florida and was successfully eradicated both times. Shell elongate-conical; 10-40 mm long in adult specimens; apex of spire usually eroded; shell with 8-12 whorls although eroded specimens may have fewer; shell usually strongly sculptured with spiral and/or vertical ribs and threads (except in Elimia dickinsoni); central tooth of radula without basal or lateral cusps (Fig. 197-209). Proc. 1982. Aperture broadly ovate. Planorbula armigera wheatleyi Low-dome Physa Female adult snail kites have yellow or orange legs and ceres; and red or orangish-brown eyes. Campeloma parthenum (Gastropoda: Viviparidae), a new species from north Florida. The sexes are separate and fertilization is internal (Andrews, 1964). Nuclear whorl 0.41 mm in diameter transverse to initial suture. 16, 17). 48). Length of shell about 2.2-2.8 mm long (Fig. Aperture large, oval, much more than half the length of shell. Dorsl surface of penis with a few elongate superior tubercles that form a weakly defined U-shaped pattern. Sci. The giant African land snail ( Lissachatina fulica (Bowditch)) (GALS) is one of the most invasive pests on the planet, causing agricultural and environmental damage wherever it is found. Armored Siltsnail Lymnaeids are a nearly cosmopolitan family of freshwater snails. 198, 205). Thompson, F. G. & R. Hershler. U-shaped superior crest not enclosing longitudinal crests. M-879 CONE SNAIL, Conus floridanus A small and less poisonous species, no one has ever died or been stung by one of these slow-movers, but like all cones, they have a venomous proboscis. Snails on corn. Penis filament white. Oftentimes you'll see trails of mucous around these damaged sites. 1905. Basch (1963) revised the classification and recognized only twelve species. The reader may be troubled by the imprecise shell characteristics that are used in the key. Shell generally thin but strong; whorls of spire strongly convex with deep suture (Figs. The Pleuroceridae of the Atlantic Coastal Plain. Pomacea paludosa, common name the Florida applesnail, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Ampullariidae, the apple snails . Taylor, D. W. 2003. Outer lip of aperture with a thick callus on inner surface. Each snail has both female and male reproductive organs, so they can reproduce rapidly. Mesa Rams-horn 121). Pomatiopsis lapidaria Shell globose with a short depressed spire; body whorl ample; umbilicus closed. Ponderous Siltsnail Combining characteristics of cranes and rails, it . 76). The HYDROBIIDAE include over 200 genera and approximately 1000 species. It was well received, and it served the interests and needs of many people. Umbilicus narrow, deep (Fig. Being nocturnal, these pests aren't always feeding when you're scouting. Shell with 4.4-5.0 whorls; about 3.7-5.2 mm long. Shell with 5.0-6.5 whorls; about 3-5 mm long (Fig. common name: tree snails of Florida scientific name: Gastropoda: Stylommatophora: Bulimulidae Introduction - Identification - Key to the Bulimulidae of Florida - Selected References Introduction (Back to Top) Many snails are found in trees, but only a few are exclusively arboreal for most or all of their life cycle. (Pilsbry and Johnson, 1903). Nuclear whorl flattened, 0.41-0.48 mm in diameter transverse to initial suture. Radial striations present on shell but not on apex. (Thompson, 1968). Base of shell when viewed from below showing about half of preceding whorl due to straight basal lip (Fig. 93). Two, Melanoides tuberculata and Tarebia granifera, are medically important because they can serve as first intermediate host for the human lung fluke, Paragonimus westermani. Shell dull. Florida. Graphite Elimia Shell about 0.38-0.41 times as wide as high and about 20-27 mm long. Periphery of last whorl bluntly angular, lying below plane of apex (Figs. Thick-lipped Rams-horn The genus is difficult to diagnose by shell characters because the three species are very dissimilar. Rock Fossaria Aperture ovate; broadly attached to preceding whorl. Rotund Mysterysnail Last whorl flattened above. Sculpture above periphery of whorls consisting of sharp spiral chords and distinct vertical ribs; shell attenuate. Flatwood siltsnail (Pilsbry, 1890). 136, 138). Shell narrow, terete or cylindric-conical with a moderately impressed suture. 145). Video. Nat. Shell distinctly carinated above and below; both apex and base funnel-shaped.