144 University of California Publications in Geology [Vol. 10 



they may become convex outward as in skull 634. In the outwardly 

 convex borders of the palate no. 634 resembles greatly species of 

 Hapalops in which the first or caniniform tooth is some distance pos- 

 terior to the end of the skull. In particular does it resemble a skull 

 of Planops longirostris illustrated by Scott. 21 In Megalonyx the 

 palate in front of M- is relatively shorter and the sides diverge 

 anteriorly more than in Nothrotherium. 



The palate is .flat or somewhat convex. It is considerably pitted 

 with large and small foramina, resembling Hapalops in this respect 

 more than Planops. , On either side of the raised median suture and 

 between the tooth-rows extends a series of large foramina. From the 

 most anterior of these, which occupy a position approximately at the 

 middle of the predental portion of the palate, widening grooves extend 

 forward to nearly the front end of the skull. Scott describes the 

 edentulous space in H. longiceps as having "a well-defined groove on 

 each external side, with raised outer border." 22 In no. 634 the 

 anterior openings of the palatine canals lie between the points of 

 greatest outward curvature of the margins of the palate. In skull 166 

 they open on the surface of the palate much more posteriorly, or 

 nearer M-, than, in the remaining skulls. 



The palatine suture, which for some distance parallels the margin 

 of the postpalatine notch, meets the middle line of the palate between 

 or behind the posterior ends of M-. The postero-internal border of the 

 alveolus for M- may be somewhat elevated, causing the palate to become 

 transversely concave in this region. The posterior opening of the 

 palatine canal opens at the anterior end of an elongate pit. The latter 

 is situated on the palatine shelf bordering the postpalatine notch, and 

 its anterior border is usually posterior to the last superior tooth. The 

 pit may, however, extend well along the inner side of M-. At the 

 posterior end of the elongate pit a second opening leads to the lateral 

 cranial wall. The large foramina, extending in a row on either side 

 of the median suture of the palate, open directly into the palatine 

 canals. 



The postpalatine notch is always more acute than in the skull 

 described by Reinhardt, and apparently reached slightly farther for- 

 ward in the Rancho La Brea species. Its position is, however, well 

 posterior to MA In Planops magnus Scott states that "The posterior 

 nares do not extend so far forward as in most of the contemporary 



21 Scott, W. B., op. cit.. pi. 59, fig. la, 1904. 



22 Scott, W. B., op cit., p. 185, 1903. 



