DISCOVERY OF THE TITANOTHERES AND ORIGINAL DESCRIPTIONS 



215 



Type. — A complete skull; premaxillaries with in- 

 cisors and canines wanting; nasals and horns partly 

 restored. Yale Mus. 2010. (See fig. 173.) 



Characters. — Marsh says: 



to the median line. The upper part of the horn cores is rugose, 

 and the base contains large air cavities. The free extremities 

 of the nasals are coossified and much elongated. They are 

 rounded in front, slightly decurved, and the surface at the end 

 is rugose. [Many other characters are listed.] 



Figure 170. — Type skulls of Symhorodon altirostris (1), S. bucco (2), and 

 Megacerops acer (3) 

 Front views. After Cope, 1874. One-sixth natural size. 



The most striking peculiarity of this cranium is the pair of 

 huge horn cores on the nasals. They are about 8 inches in 

 length and extend upward and outward. They are triangular 

 at the base, with the broadest face external. The two inner 

 faces of each core are separated by a ridge, which is continued | 



Millimeters 

 Length of skull from occipital condyles to end of nasals (36 



inches) 915 



Distance on median line from occipital crest to end of 



nasals 762 



