THE NATURAL HISTORY SURVEY. 205 
b. Depressed, periphery slightly carinated, striz rib-like, 
whorls marked by reddish flames placed‘longitudin- 
Fh ie RS et ee As LO oN MA a Sha LT alternata 
B. Shell small. 
a. Aperture devoid of teeth, spire slightly convex ....... striatella 
b. Aperture with from one to three teeth, spire flat.’........ lineata 
Suscenus PATULA Held, 1837. 
“Shell: Rather Jarge and solid, with convex spire and 
open umbilicus; whorls rounded or carinated at the periphery. 
Surface striate, ribbed-striate or spirally ribbed, obliquely 
flamed, unicolored or spirally banded; lip thin, simple.” 
“Anmal: Having a large foot, its length greater than the 
diameter of the shell, the tail rounded; sole without any traces 
i 
rel 
Fes 
STS 
Fic. 47. 
Genitalia of PyRAMIDULA. (Pilsbry, Guide to Helices, pl. xi, figs. 20, 
21.) A, P. ALTERNATA Say. B, P.sSTRIATELLA Anthony. 
of longitudinal divisions; the foot margins having a wide bor- 
der above, bounded by a distinct groove, the grooves meeting 
overthe tail. Eye-peduncles long and slender, tentacles minute. 
Mantle edge thick. Genitalia system (Fig. 47) simple, lacking 
accessory organs. Penis receiving vas deferens and retractor 
muscle at its summit. Spermatheca bulbous, its duct very 
long. Ovisperm duct very much convoluted, the ovo-testis 
consisting of small groups of large club-shaped follicles. Eye- 
