74 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



little below the middle, tuberculated on the angles, flattened and 

 sloping regularly above, flattened below; suture distinct and 

 bordered by a wrinkled collar which is ornamented with two 

 or three spiral threads ; aperture ovate, elongated into a long 

 recurved canal ; canal moderately wide ; outer lip thin and 

 simple, not lirate within; inner lip slightly incrusted; surface 

 of the shell ornamented with numerous revolving threads of 

 three alternating sizes, a few of which are coarser than the 

 others, one or two bearing tubercules on the body-whorl. 



Dimensions : — Altitude of the type specimen, 60 mm. ; maxi- 

 mum latitude of the shell, 30 mm. 



Found associated with Diplodonta parilis Conrad, Niicula 

 conradi Dall, and Tellina oregonensis Conrad. 



The ornamentation of this species is quite variable as regards 

 the prominence of the tubercules. On some specimens they are 

 pronounced while on others they are almost obsolete. 



Type: — No. 157, and cotype No. 158, Cal. Acad. Sci., from 

 the 01igocene(?) or possibly lower Miocene beds about ten 

 miles northwest of Scappoose, Oregon, in Sec. 36, T. 4 N., 

 R. 3 W. 



Agasoma oregonense, new species 

 Plate 4, figures 3a and 3b 



Shell of moderate size, fusiform; spire elevated, with seven 

 or eight whorls; whorls angulated near the middle, flat or 

 slightly convex above, cylindrical below, ornamented with 

 numerous spiral threads of alternating magnitude, and irregu- 

 larly raised axial lines of growth which are most pronounced 

 on the upper whorls where they form nodes on the angulations ; 

 suture impressed; bod5^-whorl large, ventricose, slightly con- 

 stricted in front of the suture, with a rounded shoulder at the 

 posterior third, concave above, convex below, sculptured similar 

 to the whorls of the spire, but lacking the nodes on the shoul- 

 der; aperture ovate, outer lip simple, inner lip smooth; canal 

 long and recurved. 



Dimensions : — Altitude of the t3q3e specimen, 55 mm. ; width 

 of the body whorl, 27 mm. 



Type: — No. 159, and cotype No. 160, Cal. Acad. Sci., from 

 the 01igocene(?) or possibly lower Miocene, ten miles north- 

 west of Scappoose, Oregon, locality 168. 



