FAMILY TURBINID Z— PALUDINA. 85 
upper part of the body-whorl forms a sort of shoulder with the suture. Like other specimens 
of disscisa, the apex is often truncated, and some of the specimens were filled with young 
shells. 
In my notes, I had marked specimens from Wolcott creek, Wayne county, as P. heros, 
with the following characters: ‘‘ Shell subconic, solid ; whorls 5 — 6, with moderate vertical 
wrinkles and revolving strie, becoming few and obsolete on the body-whorl; suture very 
deeply impressed ; apex depressed, polished; aperture subelliptic, narrowed above. Color, 
whitish, but covered with an olive-green epidermis ; aperture within whitish, with a slight 
reddish or bluish hue. Length, 1°5; diameter across the aperture, 0°8.” The enormous 
size of these specimens, and the absence of banded striz except on the body-whorl, induced 
me at first to consider them as distinct ; but on reéxamination, I refer them to this species. 
PALUDINA ISOGONA. 
PLATE VII. FIG. 133. 
(STATE COLLECTION.) 
P. isogona. Say, Des. terr. and fluv. shells, p. 19. 
P. pallida? LEa. 
Description. Shell short, subglobose ; surface polished with minute lines of growth. 
Whorls four or five, rounded, rapidly decreasing to the apex; body-whorl ventricose: suture 
distinct. Aperture oval, angulated above, reflected on the pillar-lip, partially concealing the 
umbilicus: outer lip slightly everted at the base. Aperture nearly twice the length of the 
spire. Apicial whorl minute, scarcely elevated. 
Color. Olive-green. 
Length, 0°25; of aperture, 0°15. 
I have received specimens of Paludina from the western part of this State, labelled 
“tsogona, Say ;” which, I am informed, is identical with P. pallida of Lea. I have not 
been able to find descriptions of the latter; but to avoid burthening the systems with a new 
name, I prefer to adopt that assigned to it by Say. 
(EXTRA-LIMITAL.) 
P. transversa. (Sav, Des. terr. and fluv. p.20.) Shell transverse, depressed-orbicular: spire convex. 
Whorls three and a half, with numerous minute slightly elevated revolving lines; suture not widely 
indented; body-whorl very convex, short; umbilicussmall. Opercle pale fulvous. Greatest width, 
- 0-4. Lowisiana. 
P. interterta. (Ip. l.c. p. 20; Am. Conch. pl. 30, figs. 3-6.) Shell subglobose, wrinkled, and 
with minute, very numerous obsolete revolving deciduous lines: spire depressed, conic, obtuse, 
truncated, eroded at tip. Whorls nearly four; suture rather deeply indented ; umbilicus closed by 
