154 



LAND AND FRESH-WATER SHELLS OF N. A. [PART IL 



Fig. 25G. 



Sii»lBOiia.i'i!l aiiiara, Reeve. — Shell ovate, depressly conoid, apes 

 anteriorly uncinate, radiately closely ribbed and 

 ridged ; black, rayed with white bands. 



Chiefly to be recognized by its white rays upon a 

 cinder black ground. {Reeve.) 



Siphonaria amara, Reeve, Con. Icon. 33. 

 California. Reeve's description aud figure 



Si2jhonaria amara. ^^^ giVen alJOVe. 



SipliOiaaria lecanilim, Philippi. — Shell small, usually ovate, 

 sometimes subcircular, projecting at the channel ; subcouic or very much 

 depressed ; ash-colored, variously colored with red ; epidermis thin, ad- 

 herent ; ribs at unequal or regular intervals, subacute or very much 

 rounded, the intervals usually with more delicate riblets ; stronger ribs 

 from twelve to twenty -two ; both ribs and riblets delicately marked by 

 radiating, subrugose strise ; ribs and internal margin sometimes white ; 

 apex sub-central, smooth, flattened ; interior black or brown, more rarely 

 white, very rarely greenish ; margin irregularly crenulated or stellate ; 

 rounded ribs projecting ; channel declining. Length of the largest flat- 

 tened form (including palmatious) .96, lat. .89, alt. .18; of a sub-conical 

 specimen, .7(3, alt. .24 inch. 



Mazatlan. (^Carpenter.) 



Siphonaria lecanium, Philippi, Z. flir Mai. IV, 51 (1846). — Carpenter, 

 Br. Mus. Cat. Reig. 182 (1856). 



The above is Mr. Carpenter's description of an extremely vari- 

 able species. lie suggests the flattened form with stout, rounded, 

 projecting palmate ribs should be called var. pahnata. 



