Vol. IV] ANDERSON AND MARTIN— NEOCENE RECORD 69 



inent, rounded axial ribs extending from suture to suture; in- 

 terspaces about equal in width to the ribs ; the spiral sculpture 

 consisting of small threads, about ten or twelve to each whorl, 

 less prominent than the axial ribs ; suture distinct, deeply chan- 

 neled; two broad continuous varices diagonally crossing each 

 whorl ; body-whorl angulated at the base, the angulation carry- 

 ing a carina ; the base sculptured with spiral threads ; aperture 

 circular; outer lip thickened ; inner lip incrusted, smooth. 



Dimensions : — Altitude of the type specimen, apex defective, 

 18 mm. ; maximum diameter of the body-whorl, 6.5 mm. 



Occurrence : — From the lower Miocene of Kern River and 

 eastern San Luis Obispo County, California. 



This species is named in remembrance of Lieutenant R. S. 

 Williamson who conducted the first exploring expedition to the 

 rich district of Kern River and Poso Creek. 



Type: — No. 145, and cotype No. 146, Cal. Acad. Sci., Kern 

 County, California, on west bank of a small canyon P/4 miles 

 northeast of Barker's ranch house. 



Genus LACUNA Turton 



Lacuna carpenteri, new species 



Plate 7, figure 21. 



Shell small, thin, conical, with six flat tapering whorls ; spire 

 elevated ; apex subacute ; whorls smooth, flat or very slightly 

 convex ; suture distinct appressed ; body-whorl large, angulated 

 at the base ; aperture ovate ; outer lip thin ; inner lip smooth, 

 separated from the body-whorl by a small umbilical chink. 



Dimensions : — Altitude of the figured specimen, 9 mm. ; 

 diameter of the last whorl, 5 mm. 



Occurrence : — Lower Miocene of Kern River, California, 

 locality 65. 



Type: — No. 147, Cal. Acad. Sci., Kern County, California, 

 on west bank of small canyon W^ miles northeast of Barker's 

 ranch house. 



Named in honor of Dr. Philip Carpenter. 



