68 



LAND AM) 1KT:.SH-"\VATER shells of X. A. 



PART IIL 



Pahidina 

 subcariaida. 



Fig. 117. Liioplax suljcarinata, Say. — Shell with, three 

 whirls, which are rounded, and subcarinated, reticulated 

 with strise and wrinkles, sometiiaes without the striae ; suture 

 deeply impressed ; apex truncated and re-entering ; aperture 

 more than half of the length of the shell, oval ; elevated lines 

 or subcarinse on the body two, three, and sometimes none. 

 Length half of an inch, breadth four-tenths. 



Inhabits with the preceding species. (Delaware River.) 

 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 advanced, broad, truncate, purplish 

 before, tail rounded behind. (Say.) 



Limnxa suhcarinata, Say, olim. Nich. Enc. ed. 1, 1817 ; ed. 2, 1818, pi. 



ii, f. 6. 

 Paludina suhcarinata, Say, Nich. Enc. ed. 3, 1819, pi. i, f. 7 ; ed. Binney, 

 p. 47, pi. Ixix, f. 7. — Haldeman, Mon., p. 8, pi. ii (1840). — De Kay, 

 N. Y. Moll., p. 87 (1843).— Chenu, Conch. 111., pi. i, f. 6-8.— 

 Philippi, Conch. II, 7, pi. ii. f. 7 (1846). — Kijster, in Chemn. ed. 

 2, p. 29, pi. vi, fig. 10-14.— Reeve, Con. Icon. 44 (Feb. 1863).— Not 



of POTIEZ ET MiCHAUD. 



Paludina sulculosa, Menke, Syn. Meth. p. 134 (1830). 



Paludina bicarinata, Potiez et Michaud, Gal. des Moll., I. 249, pi. xxv, f. 



17, 18. 

 Helix decisa, Wood, Cat. Suppl. p. 21, pi. vii, f. 17 (1S2S) ; Hanley's ed. 



226, f. 17 (1856). 

 Helix suhcarinata, Eaton, Zool. Text-Book, 195 (1826). 

 Lioplax suhcarinata, Tkoscuel, Gebiss der Schn. 100 (1857). 



There are in the mature perfect sliell 3 more whirls than the 

 number given by Mr. Say. It i.s a very 

 variable shell. The whirls are some- Fig. 119. 

 times truncated at the apex, very much 

 rounded and hardly raarted by the 

 carinas (Fig. 118), which in other locali- 

 ties are much developed, continuing to 

 the sharp, well-defined apical whirls, 

 on which is no trace of erosion (Fig. 

 119). Sometimes there is a prominent revolving 



Fig. 118. 



