56 TRTTIA. 



N. PERPiNGUis, Hinds. PI. 17, tig. 319. 



Yellowish white, obscurely marked or banded with chestnut. 



Length, -75- -9 inch. 



California. 



Fossil specimens occur much larger, and varying considerably 

 from the t^'pical form ; some of them approaching a small N. 

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

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

 ful. Schizopyga Californica, Conrad, is probably identical : it 

 is from the miocene. 



X. MENDicA, Gould. PI. IT, figs. 320-323. 



Yellowish to reddish broAvn. Length, "o-'T inch. 



Pugefs Sound to San Diego, Cal. 



N. Wo()dwar(I>\ Forbes (fig. 321), and N. Gibbesii, Cooper, are 

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

 N. trivittala, Say. 



Yar. CooPERi, Forbes. Figs. 322. 323. 



This is typically very distinct, Avith 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 

 recognized as a distinct species, it may be convenient to retain 

 its name as a variety. 



X. (Iayi, 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, Chili, Peru. 



N. rabricata, Gould (fig. 325), is a synonj-m. 



X. CoppiNGERi, E. A. Smith. PI. 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 



