ANGITREMA. 25 



pen sketch of Pleurocera verrucosa is given, which is a very 

 good representation of Mr. Say's nnpera. 



The description of the latter species is as follows : — 



Melania mtpera. — Shell oblong suboval; volutions five, slightly 

 rounded; body- whorl with about three revolving sei'ies of subequal, 

 equidistant granules or tubercles, not higher than wide, occupying 

 the superior portion of the surface ; second volution with but two 

 series ; remaining volutions with slightly elevated, longitudinal lines 

 instead of tubercles, often obsolete; spire decorticated towards the 

 tip; suture not deeply impressed ; aperture longer or as long as the 

 spire ; sinus of the superior angle profound ; labium concave, with 

 a callus near the superior angle ; columella with a slight, obtuse, 

 hardly prominent angle above the incipient sinus, which is obvious ; 

 labrum not abbreviated above, nor much produced near the base. 



Observations. — This species is common in the Wabash Eiver; the 

 spire is almost invariably so much decorticated that no trace of 

 the longitudinal lines remains; in the young only are the lines dis- 

 tinct, and even in these they are sometimes obsolete or altogether 

 wanting. It varies in the number of its series of tubercles, some 

 specimens having but one, and others, though these are rare, as 

 many as five or six. — Say. 



Melania Ilolstonia. — Shell grained, conical, somewhat thick, black ; 

 spire somewhat elevated; sutures impressed; whorls flat- p. g. 

 tened above ; aperture ovate, purple. 



Habitat. — Holston River, Tennessee. 



Diameter, -38 ; length, -79 of an inch. 



Observations. — A very distinct species with four series of 

 small, rather sharp elevations round the whorls, the two in- 

 ferior ones rather indistinct. Only two specimens have come under 

 my notice, and both have the apex decollated. — Lea. 



The figure of Holstonia is copied from Mr. Lea's plate. The 

 locality of "Holston River, Tenn.," may well be doubted. 



The species is a very common one in North Alabama, and 

 exhibits considerable variation in size and proportions. A 

 specimen in Coll. Haldeman is labelled "Nashville." 



As for Deshaj-es' Melanopsis semigramdosa, its identity is 

 proved by his quotation of Mr. Say's species as a synonj'me, 

 in his desci^ption. Say published in 1S29, Dcshayes in 1830. 

 It therefore appears that the great French naturalist, upon 



