200 ZONITES. 



Var. CUSPIDATA, Lewis. PL 60, fig. 39. 



Internal teeth strongly curved one towards the otlier, forming 

 almost an arched space ; umbilicus entirely closed. 



Monroe Co., Tenn.; Eoan ML, N. Carolina. 



- H. SUPPRESSA, Say. PL 60, figs. 40-42. 



Thin, pellucid, polished, yellowish horn-color ; whorls 6, with 

 crowded, minute, oblique striae above, and impressed suture ; 

 peristome thin at the edge, thickened within ; base rather con- 

 vex, opaque and j^ellowish white near the aperture; umbilicus 

 small, but rounded and distinct in young shells, obsolete or 

 hardly apparent in older ones ; within the peristome are one or 

 two lamelliform oblique teeth. Diam. 5 mill. 



New England to Florida, Westward to Colorado. 



See last species for distinctive characters. It is H. gularis p, 

 of Pfeiffer. 



Section HELICODISCUS, Morse, 1864. 



H. LIN EAT A, Say. PL 60, figs. 43-47. 



Widely umbilicated, umbilicus shallow, discoidal or spire 

 slightly convex; yellowish or greenish yellow; whorls 4, visible 

 below as well as above, with numerous parallel revolving lines 

 and deep suture ; within the aperture, on the external circum- 

 ference, are placed from one to three pairs of minute, conical 

 white teeth, the first pair in sight when looking into the aperture, 

 the others more remote. Diam. 3*5 mill. 



Throughout the United States, including California. 



H. FIMBRIATA, Wetherby. PL 60, figs. 48, 49. 



Widely umbilicated, discoidal or planorbiform ; light greenish 

 yellow; whorls 5, very slowly increasing, with deep suture, last 

 whorl deflected at the aperture ; aperture armed with teeth, some- 

 times as many a^asix, none of which can be seen from the mouth ; 

 umbilicus shallow, showing all the, whorls ; whorls with six to 

 eight revolving ridges, ornamented with an epidermal fringe, two 

 or three of these ridges on the upper side of the body-whorl are 

 often of such prominence as to give that portion of the shell a 

 fluted appearance. Diam. 5 mill. 



E. Tennessee, N. Georgia. 



