32 YIVIPARA. 



ViTipara suljpiirpiirea, Say. — Shell oblong, subovate, oliva- 

 ceous, with a tinge of purple more or less intense, some- 

 Fig- 55. times hardly perceptible ; spire rather obtuse, termi- 

 nating convexly ; whirls five, wrinkled, equally convex ; 

 suture impressed, but not very profoundly ; aperture 

 much widest in the middle, narrower above ; within 

 glaiicous, somewhat perlaceous ; labrum rectilinear 

 from the middle upwards ; umbilicus none. Length 

 about one inch, greatest breadth four-fifths of an inch. 

 An inhabitant of Fox River, an arm of the Wabash. 

 It is very distinct from any other species I have seen. 

 The labrum exhibits no curvature from the middle al- 

 most to its junction with the penultimate volution. 

 Shell subglobular oval, not remarkably thickened ; spire longer than the 

 aperture, entire at the tip ; whirls five, slightly wrinkled across, rounded 

 but not very convex ; penultimate volution somewhat elongated ; suture 

 impressed ; aperture ovate-orbicular, less than half the length of the shell ; 

 labium with calcareous deposit ; animal very pale bluish, with minute 

 yellow points, particularly on the rostrum, tentacula, and prominent re- 

 spiratory tube, which is as long as the tentacula ; eyes on the exterior 

 side of the tentacula, near the middle of their length ; the anterior portion 

 of the foot is very short. 



This species was first found by Mr. Lesueur and Dr. Troost, in Fox River 

 of the Wabash. In the young state the figure is subglobose, and the aper- 

 ture, although it hardly diilers in form from that of the adult, is yet longer 

 than the spire. They become proportionally more elongated as they ad- 

 vance in age, and the form, therefore, of the adult, is so different from that 

 of the young or half grown, that in these states it may, very readily, be 

 mistaken for a widely distinct species. 



The color of the shell is variable. In some it is pale horn, more tinged 

 with yellowish than with green; in others are traces of obsolete purplish 

 bands ; in many specimens the whole shell is reddish-purple, more or less 

 obscure in different individuals. 



In the autumn it is frequently found between the valves of dead Unios, 

 in which it enters perhaps to hybernate. The species is certainly allied 

 to the vivipara, but it cannot well be mistaken for it, as it is much less 

 dilated, the volutions less convex ; the penultimate volution is much 

 longer in proportion to the length of the body whirl, and the umbilicus is 

 obsolete. (iS«?/.) 



Paludina suhpurpurea, Say, 1829 ; N. H. Diss. II, 245 ; Am. Conch. Ill, 

 pi. XXX, f. 2 ; Binney's ed. p. 146, 185, pi. xxx, f. 2. — Haldeman, 

 Mon. p. 28, pi. ix, 1841.— DeKay, N. Y. Moll. p. 86 (1843).— 

 KsTiJEK, Chemn. ed. 2, p. 12, pi. ii, fig. 10-13 ; pi. vii, fig. 3-5. 



Vivipara Texana, TryOiV, Pr. Ac. Nat. Sc. (fig.), Oct. 1862. 



