22 BULIMULUS-SCUTALUS. 



white ; whorls 6, somewhat convex, rugulose-striate, crenulated at 

 the sutures. Aperture ovate, the peristome simple and acute ; colu- 

 mella twisted, inner lip dilated, covering the umbilicus. Alt. 40,. 

 diam. 17 mill. (Hupe). 



Environs of Lake Titicaca (Weddell). 



Bulimus weddellii HUPE, in Castelnau Exped., p. 45, pi. 7, f. 5,, 

 5a (1857). MORELET, Ser. Conch., iii, p. 179, pi. 10, f. 2. PFR., 

 Monogr., vi, p. 114. 



Morelet, whose remarks we quote below, enumerates three forms 

 of this species : 



a. Buff, variegated and interruptedly banded with purple-brown. 



b. Purple-brown, variegated and blotched with buff. 



c. Shell larger, more solid, ventricose, more distinctly granose- 

 striate. 



The coloration of this Bulimus is very variable. It consists of 

 irregular spots of a reddish-brown sometimes scattered at random,, 

 sometimes distributed in spiral series, on a ground of pale yellow. 

 The relation of ground-color to marking may be reversed, as is often 

 the case in the coloration of shells; the marbling becoming yellow, 

 the background reddish-brown. When this is the case the two 

 colors almost always gain in intensity. In Mr. Angrand's collection 

 there are specimens of a very deep reddish- brown variegated with 

 quite bright yellow. 



The third variety is more solid and obese than the type, with the 

 spire shorter and the granulose striation more pronounced. It ap- 

 proaches B.purpuratus Rve., but differs in the narrower umbilicus, 

 less dilated columellar margin, and the very perceptible granulation 

 of the surface. As the specimen is unique I think it better to unite 

 it to weddelli than to elevate it to specific rank. It is from Aban- 

 cay, a region equally favorable in temperature to the cultivation of 

 wheat, maize and cane. The other specimens were collected at a 

 decidedly greater elevation, around Titicaca, by M. de Castelnau, 

 and by M. Angrand, at Sorai, a cold place but sheltered, the Alpine 

 vegetation beginning to be succeeded by ligneous plants (3,500 

 meters). 



B. NEMORENSIS (' Philippi ' Pfr.). PL 4, figs. 52, 53. 



Shell perforate, ovate-conic, rather solid, longitudinally closely 

 striate and irregularly decussated by impressed transverse lines ; 

 dull buff, variegated with streaks and spots of brown. Spire conic, 



