612 GEOLOaiCAL SURVEY OF THE TERRITOEIES. 



the opposite angle nearly right and the two remaining sides flat. The 

 crown is divided into three elevated trihedral cones, one at each angle. 

 Their adjacent angles are acute, and the angle of union is fissured like 

 the same point in the sectional tooth of carnivora. The smaller lobes 

 are of equal elevation, but the crown of one is expanded so as to be 

 slightly spade-shaped. The enamel is smooth. 



Afeastirements. 



M. 



Elevation of liighest cusp .' 0.009 



Elevation of sliorter 007 



Long diameter base of crown 008 



Long diameter base of flat side 005 



The premolar is smaller, with shorter cusps, and one of the laterals 

 reduced to a rudiment. This species is near T.fallax of Marsh, but the 

 tooth he describes is narrower in proportion to its length, and has the 

 anterior lobe little over half as high. The measurements of this species 

 are somewhat larger than those given by Marsh for his T. grandu, 

 (Amer. Jouru. Sci. Arts, August 13, 1872.) 



EEPTILIA. 



OEOCODIL. 



CROCODILUS. 



Ceocodilus clavis. Cope. 



Proceed. Amer. Philos. Soc, 1872, p. 485, (Aug. 20.) 



This is a large species, with a muzzle of narrowed proportions, and 

 sufficient depth to give it a broad oval section. The nasal bones appear 

 to have reached the nasal orifice. The anterior superior teeth are very 

 large, especially the canine. The inferior tooth corresponding is large, 

 and occupies an emarginatiou which approaches near to the nasal 

 suture. The pitting of the muzzle is fine, and the swollen interspaces 

 much the wider. The teeth have stout conic crowns, with well-devel- 

 oped cutting edges, and coarse striate sculpture. The mandible is 

 acuminate to the narrow extremity, and has a long symphysis, which 

 extends to opposite the third tooth behind the notch. The cervical 

 vertebrae preserved have round cups; they have a simple elongate 

 hypopophysis, with a pit behind it ; shoulder very prominent. 



Measurements. 



M. 



JLiengtb of ramus, with teeth .■ 



Length of sy miihysis 135 



Width of ramus at end of symphysis - 085 



Width of ramus at end of mandible 020 



Width of maxillary at third tooth above 020 



Width of maxillary at notch above 020 



This species has a more slender muzzle than those described by Marsh 

 and Leidy, and is of larger size. 



Crocodilus elliottii, Leidy. 



Geological Survey Montana, 1871, p. 366. 



Abundant in the Bad Lauds. 



Ceocodilus sulcifeeus, Cope. 



Proceedings American Philosophical Society, 1872, p. 555, (October 12.) 

 A medium-sized species with cranium deeply and roughly pitted. 

 The chief character is at present visible in the teeth. The larger of 



