47 



The mantle is trifid at the base of the pillar lip, and at the upper 

 corner of the aperture ; deposits eggs the beginning of May ; eggs 

 enveloped by a transparent gelatinous substance ; the nucleus, after 

 a few days, appears of a pale or milk white color, and not so well 

 defined as those of L. catascopmm. 



Paludina subcarinata* — Shell with three whorls, which 

 are rounded, and subcarinated, reticulated with striae and wrinkles, 

 sometimes without the striae ; suture deeply impressed ; apex trun- 

 cated and re-entering ; aperture more than half of the length of the 

 shell, oval ; elevated lines or subcarina on the body two, three, and 

 sometimes none. Length half of an inch ; breadth foui'-tenths. 



Inhabits with the preceding species. Plate 1, fig. 7. 



Animal viviparous, with a chestnut, coriaceous operculum, white, 

 spotted with orange ; head pale orange, not extending beyond the 

 shell ; tentacula darker, short, subulate ; eyes situated at their base, 

 elevated, black and conspicuous ; base of the animal much ad- 

 vanced, broad, truncate, purplish before, tail rounded behind. 



Paludina Virginica.* — Shell tapering, olive, horn color or 

 blackish, under the epidermis tinged with green ; whorls seven? 

 but little rounded, crossed by curved wrinkles on the spire, and re- 

 clivate ones on the body ; a dull red line revolves near the base of 

 the whorls, and on the middle of the body a reddish-black broader 

 line, from within the upper angle of the aperture, runs parallel vrith 

 the other, and terminates near the base. Aperture subovate, more 

 than one-third as long as the shell, lip not thickened, but dilated 

 at the base. Length one inch; breadth two-fifths of an inch. 

 Plate 2, fig. 4. 



Lister's Conch, tab. 117, /r/. 7. The basilar part of the lip in 

 Lister's figure is deficient. 



Inhabitant bluish-white beneath, with orange clouds each side 

 of the mouth ; above pale orange, shaded with dusky and banded 

 with numerous black interrupted lines ; mouth advanced into a, 

 rostrum as long as the tentacula, which are darker at the base, and 

 setaceous ; base of the animal with an undulated outline. 



It often occurs in our rivers, and is readily discoverable in clear 

 water, by the channel it forms in the mud. 



*[In the earlier editions of Nich. Enc. this species was described under 

 Lymnaea. — Ed.] 



