464 



PATAGONIAN EXPEDITIONS: PALAEONTOLOGY. 



lachrymal is considerably smaller than in either of the existing genera. 

 The frontals are but slightly convex, without protuberances for the sinuses ; 

 the supraorbital border is thin and prominent, but entire, without notch ; 

 the postorbital process corresponds in position to that of Dolichotis, but 

 is somewhat shorter. The nasals are elongate and broad and their anterior 

 portion is transversely convex ; the free ends resemble those of Cavia in 

 being bluntly pointed, without deep lateral notches. 



The premaxillaries are shorter than in the modern genera, and the 

 edentulous portion of the maxillaries longer, making up nearly half of the 



FIG. 45. 



Skulls of Caviidae, left side. a. Dolichotis magellanica, x \. b. Cavia cobaya, x |. c. 

 Eocardia excavata, x \. 



rostrum ; the incisive foramina are larger and invade the maxillaries more 

 deeply. The hard palate is quite different from that of the existing 

 genera; it narrows anteriorly much less, as is determined by the lesser de- 

 gree of convergence of the dental series, and is more extensively made 

 up by the much larger palatines, and is much less reduced by the posterior 

 nares, which are smaller, extending only to m-, and are of a different shape, 

 with more nearly parallel sides and with a median spine from the anterior 

 border. The pterygoid fossae are large, but I have not been able to de- 



