216 R. 8. Lull — Fossil Dolphin from California. 



Measurements of dorsal f IX. 



Delphinavus Delphin us 



Cat. No. Cat. No. 



10040 265 



Length of centrum 38 mm 



Height of centrum, posterior end 2 1*8 



Total height, including neural spine . . 44- 1 



OQ mm 



29-5 

 110 



Ribs. — Twelve pairs of ribs are preserved in the specimen, 

 of which at least four pairs were double-headed, in comparison 



Fig. 5. 



Fig. 6. 



Fig. 5. Fourth rib. Ja lia t- size. 



Fig. 6. Sternal impressions. % nat. size. 



with five in Didelj?his and six in Phoccena. It seems hardly 

 possible that in this regard the ancient type is more specialized 

 than Delphinus, while in every other respect in which they do 

 not agree the reverse is true. The ribs are quite comparable 

 to those of Delphinus in proportions and general curvature. 



Measurements of the ribs. 



Delphinavus 



Cat. No. 



10040 



Length of first rib, measured along the chord 99 mm 

 Length of fourth rib 200 



Delphinus 



Cat. No. 



265 



120 mm 

 225 



