568 GEOLOGICAL SURVEY OF THE TEERITORIES. 



LOXOLOPHODON CORNUTUS, Cope. 



LoxolopJiodon corindus, Cope, Proceedings American Philosophical Society, 1872, p. 560, 

 (August 19;) loc. cit, 1872, p. 488, (August 22.) The short-footed Ungulata of the 

 Eocene of Wyoming, p. 8, (April 14, 1873.) Eobasileus cornntus, Cope, American N:it- 

 uralist, 1872, p. 774. Thiocerus grandis, Marsh, American Journal of Science and 

 Arts, October, 1872, (published September 21,) fide Marsh. 



Established on the remains of a single individual, which consist of a 

 nearly perfect cranium, the right scapula complete, several vertebra?, 

 including the sacral, the first or second rib, the pelvis complete, and the 

 entire right femur; also probably the proximal end of a radius. 



The species is remarkable for the narrow form of the cranium^ its 

 width at the middle being one-fourth its length. A little in front of the 

 middle are situated the horn-cores. These diverge, the upper portion 

 having an outward curvature. The base of each is triangular with 

 obtuse angles, in section, and the inner angle is the section of a rib-like 

 projection which extends across the front to its fellow and rises half 

 way up the horn-core. Above its rather abrupt termination the core 

 is transversely compressed, with oval obtuse apex. The core measures 

 M. .240 (9.5 inches) from its base in front, M. .108 (4.25 inches) in width 

 at the base behind, and .077 (3 inches) in diameter at the apex. A slight 

 swelling of the sides of the muzzle descends obliquely forward from the 

 base of each horn, which enlarges below into a prominent rib, which 

 incloses the alveolus of the canine tusk. In front of the horns the muz- 

 zle is roof-like; anteriorly it flattens out, and swells a little above the 

 posterior end of the nasal meatus. In trout of this it expands again, 

 and rises gently to the extremity of the bilobed nasal shovel, which- 

 overhangs the premaxillaries, the nasal meatus, and the greater part of 

 the apex of the nasal bones. The latter is short and with a wide base, 

 and resembles two lateral cones flattened together, their extremities 

 obliquely truncate outward and excavated. The composition of the 

 upper surface of the cranium is somewhat difficult to determine, owing 

 to the injured state of the posterior part. If we regard the bone w^hich 

 bounds the lachrymal behind and above, as frontal, as I did in originally 

 describing the species, it gives an extraordinary extent to the nasals, 

 for the common suture of these bones extends V-shaped backward, to a 

 point opposite to the middle of the zygomatic arches. It gives to the 

 nasals an extent equal to that of the frontals and parietals combined.. 

 They not only support the anterior lobes, but form the inner half of 

 the median horn cores, rising as high as the tuberosity above described. 

 To regard these bones as frontals would involve the improbable pecu- 

 liarity of their extending bej'oud the nareal orifices, and the terminal 

 cone of the nasals is not separated from them by suture, but by a groove 

 only. The question is decided in favor of their being nasals, by those 

 bones as preserved in Eohasileus ])r€ssicornis^ Cope, where the lobe is 

 represented by a tubercle only on the side of a continuous nasal. The 

 immense length of the snout in Loxolophodon looks as though the nasal 

 bones had extended themselves forward, so as to ossily the basal por- 

 tions of an elephantine proboscis. 



The frontals descend behind the horns, with a very obtuse or rounded 

 continug;tion, to the inner side of the fossa, and without any superciliary 

 margin. They form with the posterior part of the nasals a shallow me- 

 dian ba.sin. The suture with the parietals is very indistinct, but if I 

 have truly discovered it, it forms another posteriorly directed chevron, 

 and leaves but a narrow sux)erciliary portion of the frontals. Above the 



