The shell is made of calcium carbonate (limestone) and is excreted from tissue called the mantle. Many species are secondarily modified to appear right-handed or pseudo-dextral (FIGS. Schools & Childcare. Peristome incomplete around aperture. Mantle diffusely pigmented or unpigmented. 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. 172). Floridobia is known from peninsular Florida north along the Atlantic seaboard to Maine. Most freshwater hydrobiids in the eastern United States are annual species. Shell very thin, fragile, transparent. Average length about 5 mm (Figs. 34, 35) (Pomatiopsis, Fig. The venom interferes with nerve impulses, paralyzing prey in various ways. Aperture ovate; broadly attached to preceding whorl. Seashell Identification. 86). Mesa Rams-horn Penis of males with papillae along sides (Figs. Micromenetus dilatatus avus (Pilsbry, 1905). (Say, 1829). Basch, P.F. This is essential in the case of the Hydrobiidae. Elimia dickinsoni Pilsbry, H. A. Shell grayish-white. Low-dome Physa Marsh Sprite Whorls flat-sided with suture weakly impressed. Diet:  This family primarily feeds upon surface-floating jellyfish such as the Portuguese Man o' War. Bulletin of the Florida State Museum, Biological Sciences, 1: 97-239. Dusky Ancylid 91). Aphaostracon pycnus Embryonic shell with a strong peripheral spiral chord that continues onto following whorls (Fig. Proc. Apex fairly prominent as a rounded knob in the right posterior quadrant (Figs. Most species are disc-shaped or planular, as is implied by the name PLANORBIDAE. Spire usually about equal to or greater than height of aperture (Figs. Penis without a conspicuously enlarged papilla near right base, although other papillae usually are present. Conical Siltsnail Smooth-ribbed Hydrobe (Thompson, 1968). Ph.D. thesis, University of Michigan, i-xii, 1-324. Operculum with about 6 slowly expanding whorls (Fig. 101). Identify your Florida Gulf Coast seashells! Columellar margin of aperture very thick but not reflected over umbilical area (Fig.103). Regal Hydrobe Adult shells about 40 – 70 mm high (Fig. Shell olive-green with vertical reddish flames and spots. Throughout the 19th and 20th Centuries malacologists made frequent field trips to explore river systems that were poorly known, and to revisit others that were renown for their rich and unique assemblages of species. Parietal margin of operculum slightly convex in outline (Fig. Shell larger, 2.2-4.8 mm long. Malacological Review, 19: 85-86. Penis with large papilla on right margin near base and one or two papillae on left margin near distal end (Figs. (Sowerby, 1878). 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. Body whorl strongly keeled as though pinched at the periphery (Figs. Florida Press, Gainesville: i-xv, 1-68; pls. (Thompson, 1968). The basic shell morphology of the PLANORBIDAE is left-handed, or sinistral (FIGS. Height of shell about 23-26 mm (Figs. Amnicola is a widespread genus in temperate North America. Vertical ribs smooth along the periphery, strongly developed (Fig. 159-161). (Fig. The Social Vulnerability Index , which shows areas of high human vulnerability to hazards, is based on population attributes from Census 2010 (e.g., age and poverty) and the built environment. B. The ribs on the whorls are fine. First up – the snails (Class Gastropoda). Apex about 0.4-0.5 times length of shell. A single species consisting of two highly variable subspecies occurs in Florida. Operculum nearly multispiral with four large, slowly expanding whorls (Fig. 48). Newborn young about 4.5 mm in diameter (this can be determined by removing juveniles from brood pouch). Umbilicus closed or narrowly perforate. Formalin does not even serve as a good fixative or preservative for long-term anatomical studies. Maximum size 1.5 inches. 1945. As was anticipated, further work on the systematics of the southeastern freshwater snail fauna created the need for subsequent revision in 1999, and for this updated version. Umbilicus narrow, without a strong circum-umbilical ridge, outer lip without a callus on inner surface. Shell conical to elongate-conical; whorls 4.0-4.5 with a deeply impressed suture. Pilsbry, H. A. (Jay, 1839). 1991. Penis with different arrangement of papillae than above. Ampullariids hav… Vas deferens independent of blind caecum and its duct. (Walker, 1905). Thin and translucent or transparent. Penis with two or more longitudinal crests within U-shaped superior tubercle (Fig.