Vol. VII] DICKERSON— CLIMATE AND OLIGOCENE FAUNAS \77 



parallel to the axis ; one beaded intercalary thread with small 

 beads twice as numerous nodes occurs in addition ; suture wavy, 

 indistinct, canal short. 



Dimensions: — Length, 13 mm. ; width of body-whorl, 3 mm. 



Type:— No. 421, Cal. Acad. Sci. Locality 181, near Vader, 

 Lewis County, Washington, on east bank of the Cowlitz River, 

 just back of the Greeco ranch house, about four miles east of 

 Vader. Colls., F. M. Anderson and Bruce Martin. 



Named for Mr. Bruce Martin, who collected the type speci- 

 men. 



Molopophorus stephensoni, new species 



PI. 30, Figs. 10a and 10b 



Shell small, rugose, solid with four whorls; nuclear whorls 

 smooth, large; third and fourth whorls characteristically 

 marked by nodose collar which is definitely set off by a rounded 

 groove from the lower portion of the whorl ; third and fourth 

 whorls decorated by 12 sharp axial ribs crossed by equally 

 spaced spiral threads; suture wavy, sunken; canal short, re- 

 curved with strong siphonal fasciole. 



The young individual figured has about 18 slightly sinuous 

 axial ribs instead of 12. 



Dimensions: — Length, 13 mm. ; width of body-whorl, 8 mm. 



Type:—l<lo. 422, cotype 423, Cal. Acad. Sci. Locality 181, 

 near Vader, Lewis County, Washington, on east bank of the 

 Cowlitz River, just back of the Greeco ranch house, about four 

 miles east of Vader. Colls., F. M. Anderson and Bruce Martin. 



Named in honor of Dr. L. P. Stephenson of the U. S. Geo- 

 logical Survey. 



Strepsidura packi, new species 

 PI. 30, Figs. 11a and lib 



Shell fusiform, with seven whorls; the first four naticoid; 

 the fifth and sixth whorls decorated by about 12 pointed nodes 

 located medially and marking a prominent shoulder; a flat 

 sutural band is found just beneath suture on last three whorls; 

 space between sutural band and nodes covered by undulating 

 spiral threads, two on fifth, six on sixth, nine on body whorl ; 

 space between suture and nodes similarly decorated ; body whorl 

 large, being two-thirds of shell length, marked by three rows 



