

family. turbinidie — melania. 91 



Melania bizonalis. 



PLATE VII. FIG. 140. i. B. 



(STATE COLLECTION.) 



Description. Shell tapering, elongated. Whorls seven or eight, flattened; the upper whorls 

 with a revolving strongly carinated line just above the suture, and above this two slightly but 

 distinctly elevated revolving lines ; all the volutions with sinuous vertical elevated lines 

 becoming obsolete towards the tip. Aperture subovate, angular above, and uniting with a 

 broad white callus on the pillar-lip : tip rarely perfect. 



Color. Olivaceous-brown. Epidermis with two and rarely three dark reddish revolving 

 lines on the body-whorl, often indistinct, but may be traced. 



Length, - 7; of aperture, 0-23. Width of the same, # 16. 



For this species I am indebted to Dr. Emmons, who found it abundantly in Lake Cham- 

 plain. It approaches M. virginica, but, as I view it, very distinct by its flattened whorls 

 and deep angular sutures. 



Melania gemma. 



plate vii. fig. 1«. 



(STATE COLLECTION.) 



Description. Shell moderately large, oblong : spire attenuated, acute ; the whole surface 

 covered with waved vertical wrinkles. Whorls eight, all distinctly carinate near the middle, 

 and very acutely so on the apicial whorls ; on the lower whorls this carina is below the middle, 

 but becomes medial above ; in some specimens, the lower whorls are bicarinate, or rather the 

 carina is slightly furrowed on its edge. Suture deep, occasionally cancellate. The body- 

 whorl has one or more rounded grooves on each side of the carina, which produces corres- 

 ponding minute elevated ridges. Lip fragile ; its margin convex, rarely perfect. 



Color. Variable from straw-yellow to amber and dark reddish brown ; columella often 

 purple ; lower sutures opake white. 



Length, 0-7- 1*2; of aperture, 0-23. 



This species was obtained from Mud creek, Onondaga county, by Dr. Budd, and was at first 



referred to the semicarinata of Say, hitherto supposed to be an exclusively western species. 



An attentive examination and comparison of Say's description with this, will exhibit strongly 



marked differences. It is larger ; all the volutions are carinate, and the sutures distinctly 



cancellate. I have received others from the Erie canal, much larger, being more than an 



an inch long. In these the revolving groove, in descending, gradually approaches nearer the 



suture, and is continued on the body-whorl, which is vertically rugose. In my catalogue of 



species, I had named this species after its discoverer ; but the practice has been so much abused 



that it is daily becoming obsolete. I trust that the name now proposed will readily suggest 



that of the gentleman to whom I have been under many obligations in this department. 



•12 



