THE NATURAL HISTORY SURVEY. 143 
B. Aperture with well-developed teeth. 
a. Parietal wall with one, peristome with two teeth. 
1. Perforate. 
*Spire depressed, parietal tooth depressed, curved, 
| ey Wa eee pra Mee SS oo 8 LS a TA oe ih UA 6 bi es A he tridentata 
**S pire rather elevated, parietal tooth elevated, almost 
Stratoht ath ie lowe em weer seats Sarele beverchaterate Jraudulenta 
De LPATIGREORALE Surg an Septet Le wisi al otk SroruiaSda oh ane Baie d aupioe Rode infiecta 
b. A single large tooth on the parietal wall. 
1. Imperforate; peristome notched and continuous with 
parietal toot... ee sate et acwis 6 elie easton des vee hirsuta 
2. Perforate to imperforate; peristome simple, not contin- 
SOUS Wit parietal fail wich cited oF digesta aie tase ok monodon 
Section TRIODOPSIS Rafinesque. 
“Shell: Varying from depressed to globose-conoidal, um- 
bilicate or imperforate; surface generally striated; whorls five 
to six, the last wider, more or less deflexed in front. Aperture 
lunate, typically obstructed by three teeth, two on the lip, one 
on the parietal wall; but any or all of the teeth often absent.” 
(Pilsbry, l. c., p. 74.) 
51. Polygyra inflecta Say, pl. xxx, fig. 5. 
Flelix infiecta SAY. Journ., Phil. Acad., Vol. II, p. 153, 1821. 
flelix clausa FERUSSAC. Tab. Syst., p. 38, No. 104; Hist., pl. xlix, fig. 2. 
Shell: Depressed, solid, imperforate; surface covered with 
coarse striz, the spaces between the striz being twice or three 
times the width of the striz, and the shell with numerous hair- 
like projections scattered over the surface; apical whorls 
minutely striate; periphery subangulated; sutures impressed; 
whorls five, convex, rather closely coiled, the last whorl consid- 
erably constricted behind the reflected peristome, so that the 
edge of the reflected lip is on a level with the body-whorl; 
spire very much depressed, slightly convex; aperture con- 
tracted, armed with three teeth; the tooth on the outer lip is 
tubercular and situated just below the periphery, a little deep- 
seated; the tooth on the basal lip is also tubercular, and placed 
at about the center, not deep-seated; the points of both teeth 
point inward, and there is a marked circular sinus between 
them; the parietal tooth is long, white, narrow, curved, elevated, 
begins at about the center of the parietal wall, and extends in 
an oblique direction until it meets the reflected peristome and 
the umbilical region; peristome thick, white, reflected; umbili- 
cus closed, but the region indented; base of shell flat-convex. 
Greater diameter 11.00; lesser, 10.00; height, 6.00 mill. (8446), 
