The Nautilus. 



Vol. XVIII. MAY, 1904. No. 1. 



TWO NEW SPECIES OF PLEUROTOMA FROM CALIFORNIA. 



BY WILLIAM JAMES RAYMOND. 



Subgenus Genota H. and A. Adams. 



Section Dolichotoma Bellardi. 



Pleiirotoma ( Genota) stearnsiana, new species. 



Shell broadly fusiform, spire acute, outline of spire moderately 

 convex; whorls eight and one-half, convex anteriorly, slightly con- 

 cave near the suture, the margin at the suture strongly appressed ; 

 suture distinct; aperture longer than the spire; color orange to cream, 

 a broad, spiral, brown band below the suture and nine or ten narrow, 

 clearly-defined bands on the last whorl, one or two of these also visible 

 on the spire, bands nearly as wide as the lighter interspaces; interior 

 of aperture yellowish, lighter within and spotted with brown on the 

 outer lip by the external bands; first two whorls smooth, later whorls 

 with numerous revolving threads, closely beaded on the spire by in- 

 cremental lines which follow the outline xjf the lip, threads not 

 beaded below the periphery of the last whorl, but roughened by the 

 growth-lines and somewhat coarser anteriorly; aperture rather 

 narrow; posterior sinus shallow, rounded; lip acute, produced below 

 the sinus, canal wide; pillar solid, somewhat curved, obliquely 

 truncate below. Operculum normal. Long, of shell 30.5, of aper- 

 ture and canal 17, of body-whorl 23 mm.; max. diam. 13 mm. 

 Divergence 50°. An extremely old specimen which shows a thick- 

 ening of the pillar like an obscure fold, measures: long, of shell 41 .5, 



