215 



Turbo. 



squamulosus. . conoidal, pointed, umbilicated ; whirls convex, 

 with five squamose grooves — not ^ an inch. 



radiosus — globosely conoidal, five whirls deeply sulcated in the 

 middle, above and below radiately striated — small. 



helicinoides. . depressedly conoidal, polished, a little spotted ; 

 four whirls, smooth ; base rather callous. 

 Resembles troch. vesfiarius, Lin. 



denficulatus. . globosely conoidal, transversely striated ; whirls 

 four, with two denticulated keels in the middle ; base um- 

 bilicated — -very small. 



Delphinula. 



calcar. . spire depressed ; whirls rough, keeled in the middle, 

 keel armed with spines — nearly 1 inch wide. 



lima. . orbiculato-convex, rough, transversely striated, echinated 

 with concave squamous striae ; whirls round, but sub- 

 angulate — f inch. 



conica. . conically pyramidal ; whirls smooth but bicarinated, 

 last turn disjoined — small. 



turbinoides. . obtusely conical, whirls obsoletely keeled, with 

 minute strise — small. 



marginata. . roundish ; whirls smooth, umbilicus lessened by a 

 border — small. 



striata, . roundish, transversely striated ; whirls subangular ; 

 umbilicus spiral — very small. 



sulcata. . roundish, depressed ; whirls deeply sulcated, lip ser- 

 rated — very small. 



canalifera. . roundish ; smooth ; margin of the umbilicus plaited; 

 a canal passing spirally up its sides — very small. 



Cyclostoma. 



comupastoris. . orbiculato-convex ; transversely striated, whirls 

 round, detached at the base, . very small. 



spiruloides. . orbicular, smooth, pellucid. . very small. 



planorbula. . round, solid, umbilicated beneath. . very small. 



macrostoma. . orbicular, pellucid, mouth very open. . minute. 



mumia. . cylindraceo-conical ; solid, longitudinal and trans- 

 verse striae ; opening ovate, . f inch, 



turritellata. . turreted ; turns convex, with decussating striae. . 

 very small. 



Planorbis. 



nitidula. . smooth ; polished ; opening roimd. . very small. 

 subangulata. . obsoletely carinated ; opening round but rather 



angular. . very small. 

 bicarinata. . transversely striated ; bicarinated. 

 spirorbis. . belongs, perhaps, to delphinula. 



Scalaria. 



crispa. . turreted ; ribs numerous, subangulated at the base ; 

 whirls ventricose — | inch. 



