142 FOSSIL MAMMALIA. 



In other points this fossil dolphin differed essentially from 

 the congeners we have named. The head was much more 

 narrow in proportion to the length, the muzzle much longer in 

 proportion to the cranium, the orbit smaller, and the indention 

 before the nostrils more narrow and more hollowed. 



In the dimensions of the other parts similar differences ex- 

 isted, and M. Cortesi calculates, with great probability, that 

 the animal was nearly thirty feet long. 



On the whole, the Baron concludes that it belonged to a 

 species different from those of any of the genus now existing. 



Another dolphin, with a peculiarly long symphysis of the 

 lower jaw, was discovered in the falun of the department of 

 Landes, at Sort, a village two leagues from Dax. This falun 

 is very abundant in shells and other marine productions. 



A tolerably complete jaw of this dolphin is in a collection 

 made by M. de Borda d'Ovo, and attached to the town of Dax, 

 along with another fragment containing some teeth. 



The peculiar character is the length of the symphysis, to 

 which no living dolphin approaches, except the front atus, and 

 the species of the Ganges. Both these, however, are much 

 smaller, and differ somewhat in the form of this part and of the 

 teeth, and in the number of the latter. The conclusion from 

 these and other considerations is, that the species to which this 

 dolphin belonged is unknown, at least as far as our very im- 

 perfect knowledge of the cetacea will bear us out in such a con- 

 clusion. 



In the formation above mentioned was also found a portion 

 of lower jaw, indicating a species very near the common dol- 

 phin, but with some slight differences. 



A portion of upper jaw, found in the calcaire grossier of 

 the Orne, seemed also to belong to a dolphin different from 

 any known species. The characteristic distinction is, that the 

 pyramidal and descending projection of the back nostrils begins 

 to be visible opposite to the last molars. This is not the case 

 with any living dolphin with which we are acquainted. 



