50 TRITIA. 



X. PERPINGUIS, Hinds. PI. 17, fig. 319. 



Yellowish white, obscurely marked or banded with chestnut. 



Length, -T5--9 inch. 



California. 



Fossil specimens occur much larger, and varying considerably 

 from the typical form ; some of them approaching a small N. 

 fossata in size and latitude. P. P. Carpenter considers X. in- 

 terstriata, Conrad, a fossil equivalent which is somewhat doubt- 

 ful. Schizopyga Calif or nir-a^ Conrad, is probably identical : it 

 is from the miocene. 



X. MENDiCA, Gould. PL 17. fio-s. 320-323. 



Yellowish to reddish brown. Length. *5-'7 inch. 



Pugefs Sou Ml to San Diego, Cal. 



X. Woodwardi, Forbes (fig. 321), and ' X. Gibbesii, Cooper, are 

 synonyms of this species ; which is the Wrst Coast analogue of 

 N. trivittata, Say. 



Yar. COOPERI, Forbes. Figs. 322,^323. 



This is typically very distinct, with its seven or eight distant, 

 prominent, shouldered ribs, but specimens are not rare which, 

 commencing with the numerous ribs of N. mendica, suppress 

 alternate ones and increase the prominence of those remaining 

 on the body-whorl. There are also specimens intermediate in 

 form and number of longitudinal ribs, and even some in which 

 the ribs are obsolete on the body-whorl. As it is generally 

 reeooTii/A'd as a distinct species, it may be convenient to retain 

 its 11 nine MS n variety. 



N. UAYJ, Kiener. PI. 17, figs. 324, 325. 



Yellowish brown to chestnut-color ; longitudinal sculpture 

 usually the most prominent, but sometimes obsolete ; a row of 

 bead-like granules usually, next below the sutures. 



Length, 15-18 mill. 



W. Coast of So. America, ( 1 hiU, Pern. 



X. rubricata, Gould (fig. 325), is a synonym. 



X. COPPINGERI, E. A. Smith. PL 18, fig. 372. 



Whitish, with a broad purplish-brown band at the top of the 

 whorls, and two others on the last, the upper one around the 



