76 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D vSer. 



broadly rounded, denticulate with fine ridges on the inner margin; aperture 

 narrow, somewhat S-shaped, a little wider at anterior end; shell notched both 

 before and behind; inner lip rounded, not known to be toothed; surface 

 smooth and polished. The outer lip is slightly expanded posteriorly in an 

 ear-like elevation that rises to a level with the low spire. The anterior end 

 of the inner lip is bent a little downward just before reaching the forward 

 notch. Both notches are somewhat shallow, the posterior one showing an 

 upward curve or groove between the spire and the ear-like expansion of the 

 outer lip. 



Occurrence. — One good specimen of this shell was found 



at the Smith ranch, Oregon. 



10. Gyrodes siskiyouensis, sp. nov. 

 Plate VIII, Figs. 167 and 168. 



Shell moderate in size, subglobose, though a little compressed, spire low; 

 upper surface a little flattened near the suture, forming a narrow ledge and 

 angle; the whole surface plainly marked by revolving lines, most developed 

 near the angle above; umbilicus open and slightly angled; no lines of growth 

 visible, except on perfectly preserved shells. 



Occurrence. — This shell is common on the north slope of 

 the Siskiyou Mountains, in the Chico beds. It occurs 

 with Dcsmoceras ashlandicum, and CuciiUcea truncata, and 

 many other gasteropods and bivalves that belong to the 

 Chico. 



II. Anchura condoniana, sp. nov. 



Pl.\te \III, Fig. 179. 



Shell large, robust, with high spire; whorls about eight in number, moder- 

 ately rounded; surface of spire ornamented by twenty or more longitudinal 

 ridges; body-whorl entirely covered by longitudinal and revolving ridges 

 equally developed; lip long and falcate, extending laterally, but bearing a 

 spur-like process near the spire; lip strongly angled along the back, with 

 angle extending upon the body-whorl; lip also bearing an angle on its outer 

 margin. 



Occurrence. — This species was found in the Lower Chico 

 beds of the Forty-nine Mine, near Phoenix, Oregon, asso- 

 ciated with many species of Schlcenbackia and Scaf kites. 



