CRETACEOUS FOSSILS. 107 



been collecting there for months, I have not seen even a single fragment that 

 could by any possibility be referred to this species. 



DOSINIA, Scopoli. 



D. ELEVATA, G. 



PI. 30, Fig. 252. 



(D. alia, Con. (non Dkr.) Pacific E. R. Report, vol. 5, p. 320, pi. 2, fig. 2.) 

 (Not D. alta, Con., Proc. Phila. Acad. Nat. Sci., 1856, p. 315.) 



Subcircular, convex, thick; beaks prominent, placed in ad- 

 vance of the middle, and strongly inclined forwards ; base and 

 ends regularly rounded; cardinal margin strongly arched and 

 uniting with the posterior end by a faint angle; immediately 

 adjoining the ligament there is an inward truncation of the car- 

 dinal border, which runs from the beaks to the posterior angle, 

 and is nearly a quarter of an inch broad at its widest part. 

 Lunule very faint. Surface marked only by lines of growth. 



Figure, natural size. 



Locality: Near Fort Tejon. Dr. Horn. 



Dosiniaalta, Con. (not Dunker), was described, by Mr. Conrad, from the Miocene 

 formation of Monterey, in 1856. Subsequently, he applied the name to the Creta- 

 ceous form from the Canada de las Uvas, on the evidence of a specimen in even a 

 more fragmentary condition than the present one. By comparing fig. 252 with 

 his original description, or with the figures in vol. 6, Pacific R. E. Report, pi. 3, 

 fig. 13 a, 13 b, it will be seen at once that the two species are not of the same form. 



This form approaches D. infiata, from Chico Creek, but is larger, thicker, broader, 

 and less convex. That species also wants entirely the truncation of the cardinal 

 margin. 



D. PERTENUIS, n. S. 

 PI. 30, Fig. 253. 



Shell broad, very thin, subcircular ; anterior and basal mar- 

 gins forming a regular curve, cardinal margin nearly straight; 

 posterior end obtusely subangulated ; beaks small, in advance 

 of the middle and inclined forwards. Surface marked by fine 



