498 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxni. 



the eleventh, and 34 upon the next, the penultimate turn. On this 

 whorl the axial ribs are less regular and less strongly developed, show- 

 ing senile degeneration. Peripher}' of the last whorl well rounded. 

 Base short, well rounded, marked by slender continuations of the axial 

 ribs which extend feebly to the insertion of the columella. Entire 

 surface of spire and base crossed by numerous closely placed spiral 

 striations. Aperture subquadrate, posterior angle obtuse, outer lip 

 thin, columella rather strong, somewhat oblique, and slightl}^ revolute, 

 without apparent fold in the aperture. The type has 13 whorls and 

 measures: Length 7.7 mm., diameter lA mm. 



The type and seven specimens were collected by Mr. S. S. Berr}^ in 

 12 fathoms ofi' Del Monte, Monterey, California, five of these are in 

 Mr. Berry's collection, the type and one other form Cat. No. 196198, 

 U.S.N.M. Cat. No. 196200, U.S.N.M., contains a specimen from 40 

 fathoms off Pacific Grove, Monterey, California, dredged l)y Mr. 

 Berry. Another specimen in Mr. Berry's collection was dredged in 

 shelly sand at Monterey, California, at a depth of 29 fathoms. 



This species is nearest related to StrlotiirhnuUla styllna Carpenter, 

 but can readily be distinguished from it by its less rounded whorls, 

 straighter and much stronger ribs, and ])\" having the ribs continuing 

 over the base and scarcely an}' space showing between the termination 

 of the intercostal spaces and the suture. 



Subgenus PYROOLAMPROS Sacco. 

 Pyrgolampros Sacco, I. Moll, del Piemonte e della Liguria, 1892, p. 85. 



Turbonillas with low, broad, rounded vertical ribs which almost 

 always disappear as they pass over the periphery and base of the last 

 whorl, and many very fine, faint, wavy spiral striations; surface 

 covered by a thin epidermis. Columella usuall}' somewhat flexuose. 



Ti/pe. — P. Tnloperplicatuius Sacco. 



All our west American species are of a light-yellow to chocolate- 

 brown color. The intercostal spaces are not depressed as in Chent- 

 nitzia^ but appear as simple shallow undulations between the axial 

 ribs. The spiral striations, in perfect specimens, appear as if they 

 were situated beneath the light-colored epidermis and were shining 

 through it. 



KEY TO SPECIES OK PYRGOLAMPROS. 



Vertical ribs present 



■ Shell large, adult more than 10 mm. long (dark brown) taylori. 



Shell less than 10 mm. long when adult. 

 Shell very slender, brown banded. 



Space between the sutures dark l)rown with two light brown bands. 



berryi. 



Space between the sutures white on the jjosterior half and brown on 



the anterior half , lyalli. 



