406 Miscellaneous. 



Miocene embraced several genera and species of horned giants not 

 very unlike the Eohasileus and Uintatherium in their armature. 



While exploring, in connexion with the United States Geolo- 

 gical Survey of the Territories, I discovered a deposit of the remains 

 of numerous individuals of the above character, which included, 

 among other portions, crania in a good state of preservation. Most 

 of these skulls are nearly or quite 3 feet in leng-th, and mostly 

 deprived of their mandibular portions ; these are quite abundant in 

 a separated condition. The crania represent at least six species, 

 while the mandible represents a condition distinct from that of Ti- 

 tanotheriinn or any allied genus, viz. I. 0, C. 1, P.M. 3, M. 3. 

 The teeth diminish rapidly in size anteriorly ; and there is no dia- 

 stema behind the canines, whose conic crowns do not exceed those of 

 the premolars in length. To the genus and species thus charac- 

 terized I have elsewhere given the name of Symhorodon torvus. 



One of the crania, referred to under the name of Mlohasilens 

 ophryas, is characterized by its strong and convex nasal bones and 

 concave superior outline posteriorly, and by the presence of a 

 massive horn-core on each side of the front, whose outer face is con- 

 tinuous with the inner wall of the orbit, as in the Loxolophodon 

 cornutus. It stood above the eye in life, and diverged from its fellow 

 so as to overhang it. In the specimen which was fully adult 

 they were worn obtuse by use — length about 8 inches, thickness 

 3 inches. The molar teeth differ from those of Titanotherium 

 Proutii in having cross crests extending inward from the apices of 

 the outer chevrons, each of which dilates into a T-shape near the 

 cones. 



The third species is referred to the new genus Symhorodon, under 

 the name of S. acer. It has overhanging eyebrows and the vertex 

 little concave ; but the nasal bones are greatly strengthened, and 

 support on each side near the apex a large curved horn-core 10 

 inches in length with sharply compressed apex. These horns 

 diverge ■o'ith an outward and backward curve, and when covered 

 with their sheaths must have considerably exceeded a foot in length. 

 This was a truly formidable monster, considerably exceeding the 

 Indian rhinoceros in size. 



The fourth species is allied to the last, and has well developed 

 superciliary crests without horns. The latter are situated well 

 anteriorly, and are short tubercles not more than 3 inches in 

 height. They are directed outward, and have a truncate extremity. 

 The type individual is of rather larger size than those of the other 

 species. There are several crania referable to the three now named. 

 The present one has been named Symhorodon helocerus. 



Other species, based upon crania without mandibles, were referred 

 to the genus Symhorodon. 



These animals show true characters of the Perissodactyla in their 

 deeply excavated palate, solid odontoid process, third trochanter of 

 femur (which has also a pit for the round, ligament), the divided 

 superior ginglyraus of the astragalus, &c. — Read before the American 

 Association for the Advancement of Science, Portland Meeting, 

 August 20, 1878. 



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