ART. 26 EEMAINS OF FOSSIL PORPOISES KELLOGG 1 1 



lae and the corresponding underlying lateral extensions of tlie 

 frontals roof over the temporal fossae, but the former do not come 

 in contact with the supraoccipital posteriorly because of the pres- 

 ence of a narrow intervening strip of the frontal. The outer mar- 

 gins of both maxillae are imperfect above the temporal fossae. The 

 surface of the maxilla is somewhat depressed opposite to the nasals 

 and slightly convex above the supraorbital plates of the frontals. 

 The concavity is most evident above the temporal fossa. Two rather 

 large foramina which connect with the infraorbital canal are pres- 

 ent on each maxilla above the temporal fossa, and of these the an- 

 terior one is the larger. The internal margin of the maxilla, with 

 the exception of that portion Avhich overlaps the frontals on the 

 vertex, is in contact with the premaxilla for practically its entire^ 

 length. There are three additional foramina in each maxilla. The 

 most i^osterior one of these is situated a little behind the notch, and 

 from it there is a deep channel leading in a postero-external direc- 

 tion. The external border of the maxilla is convex in front of the 

 maxillary notch, but this portion of the maxilla is relatively thin. 

 Further forward the thin outer edge gradually disappears with the 

 lateral compression of the rostrum and the maxilla appears to be 

 deeper from a side view, but this is due to the outward and down- 

 ward curvature of the dorsal surface. In correlation with this 

 tapering, the maxilla decreases in breadth anteriorly and the sides 

 become more nearly vertical. For a distance of about 250 mm. in 

 front of the maxillary notch the inner border of the maxilla fits 

 closely to the outer border of the premaxilla, but at this point a 

 foramen appears between them, succeeded anteriorly by a broad and 

 rather deep groove. This groove does not follow the inner margin 

 of the maxilla, but extends directly forward, finally occupying the 

 :-ide of the maxilla and disappearing before reaching the end of 

 the rostrum. 



(Jn comparing the dorsal view of the skull of EurhinodelpMs 

 CGcheteuxl ^^ with this specimen, it was noted that the breadth of 

 the anterior margin of that portion of the maxilla which overlies 

 the supraorbital process of the frontal was proportionately less 

 and that the maxilla sends forward a narrow projection which re- 

 duces the maxillary notch to a narrow groove. Although no an- 

 terior projection is present on the skull of Eurhinodelphis loncfl- 

 rost/is ^^ this portion of the maxilla is even narrower than in 

 cocheteuxi. According to the figures used by Abel, the lachrymal 

 is not visible from a dorsal view of the skull in either longirostris 

 or cocheteuxi. A small portion of the anterior end of the lachrymal 

 projects forward in the left maxillary notch on the skull of 



i^Abel, O., Les dauphins longirostres du Bold^rien (Miocene sup^rieur) des environs 

 "Abel, O., Idem, vol. 2„ p. 11, 1902. 



