FAMILY LIMNIADE — LIMNEA, 67 
GENUS LIMNEA. Lamarck. 
Animal spiral, elongated or oval. Head with two flattened triangular tentacles, with the eyes 
at their internal base. Mouth surmounted by a free thin movable appendage. Foot oval, 
bilobed in front, contracted behind. Breathing orifice on the right side, narrow, oblong, 
and covered by a fleshy appendage which borders it beneath: vent near it. Generative 
organs distant: the male under the right tentacle ; female near the breathing orifice. Sexes 
united in the same individual. Shell thin, dextral, oval, elongated; spire more or less 
acute and elongated: aperture longer than wide, oval, occasionally very large ; lip thin; 
an oblique fold on the columella. 
Oss. The animals of this genus inhabit fresh water streams, or their vicinity, feeding on 
aquatic animalcule. ‘The American species have been carefully studied and beautifully illus- 
érated by Mr. Haldeman, 
LIMNEA CATASCOPIUM. 
PLATE V. FIG. 80. 
(STATE COLLECTION.) 
Lymnea catascopium. Say, Nich. Ency. Vol. 4, p. 2, fig. 3; Am. Conchology, pl. 55, fig. 2. 
L. pinguis? var. Ip. Jour. Acad. Nat. Sciences, Vol. 2, p. 123, 
L. decollata. ApAmMs, Bost. Jour. Nat. Hist. fide Haldemani. 
Tis catascopium. GouLD, Invertebrata of Massachusetts, p, 223. 
L id, HaLpemMAn, Monog, of the Limniades, No. 3, p. 6, pl. 1, figs. 1-12. 
Description. Shell smooth and polished, oblong-ovate. Whorls four or five, convex, with 
wrinkled incremental lines, and rapidly tapering to an acute apex: body-whorl large and ven- 
tricose: spire shorter than the aperture: aperture ovate. Lip simple, thick, and regularly 
curved : pillar-lip concave, witn a distinct fold. 
Color. Yellowish horn or blackish. Animal yellowish brown, minutely punctate with light 
yellowish: foot rounded behind. 
Diameter, 0°2-0°4. Height, 0°5-0°7. 
T have followed Mr. Haldeman in uniting the pinguis of Say with the above. Common in 
the western district of this State. It ranges from Massachusetts to Delaware, and west- 
wardly through the Northwest territory. 
o* 
