370 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
Locality Santa Cruz quadrangle, Santa Cruz County, locality 
No. 108, on road between headwaters of Boulder Creek and South 
Fork of Waddell Creek, about a mile north of Eagle Rock. (R. 
Arnold.) 
Genus STREPSIDURA Swainson. 
STREPSIDURA CALIFORNICA, new species. 
Plate XXXITI, 1nkegy AA 
Description.—Adult shell attaining an altitude of at least 40 mm., 
broadly fusiform; spire elevated; apex acute. Whorls 5 or 6, upper 
whorls prominently angular, body whorl biangular with a very faint 
suggestion of a third angle below the other two; posterior margin of 
each whorl appressed against the middle of the antecedent whorl, 
covering the lower angle of the latter; upper portion of whorl flat 
or concave, middle of whorl between angles, exceedingly concave; 
angles ornamented by several (13 on body whorl of type) prominent 
sharp nodes which protrude straight out from the angle, flexing 
neither backward nor forward, and merge into faint or obsolete 
axial ribs on the body of the whorl; posterior portion of whorl show- 
ing a faint sutural carina; three uppermost whorls less prominently 
nodose but rather more cancellate than the lower ones; surface sculp- 
tured by numerous, sometimes alternating, sometimes subequal, raised 
revolving lines; these lines are usually much finer and closer set on 
the angles than on the body of the whorl; fine incremental lines are 
also plainly seen over much of the surface, especially the lower por- 
tion of the body whorl, and sometimes irregular lines of interrupted 
growth cross the whorls approximately parallel with the axis of the 
spire. Suture deeply appressed, slightly wavy. Pillar short, basal 
portion turned outwardly with a biangular fold at the base of the 
aperture. Aperture subpyriform. 
Dimensions.—Altitude, 32 mm.; latitude, 23 mm.; altitude of body 
whorl, 22 mm. 
Notes.—S. californica is allied to S. oregonensis Dall from the 
Eocene of Oregon, but is distinguished from the latter by its some- 
~what sharper spire, much more strongly angulated and nodose whorls, 
coarser revolving lines, and less well-defined third angle on the lower 
part of the body whorl. 
Type.—Cat. No. 165450, U.S.N.M. 
forizon.—San Lorenzo formation, Oligocene. 
Localities.—Santa Cruz auadranele Santa Cruz County, locality 
No. 103, near mouth of Kings Creek; locality No. 108, on road near 
cuanicle Between nee borates of “ule Fork of Waddell Creek and 
io proreccionel Pave No. 59, We Relient: Stee “il 11, fig. 6, 
