640 GEOLOGICAL SUKVEY OF THE TERRITORIES. 



Another pectoral spine is larj^or ; diameter at base, .010. 



From the Mammoth Buttes and Laclede, on South Bitter Creek.* 



Bhineastes calvus. Cope, sp. nov. 



"Represented by numerous specimens, including most parts of the cra- 

 nium, spines, &c. 



One of these shows the supraoccii)ital production to have the form 

 of an equilateral triangle, with a sinus of the posterior border on each 

 side of it which advances iu front of the epiotic bone below. Shortly iu 

 front of this point the deep groove representing the fontanelle com- 

 mences. The cranial rug;c are lines parallel to the fontanelle, which 

 diverge to the margins of the occipital i)rolongation, and are frequently 

 connected by cross-ridges. The frontal portion of the skull is much 

 expanded laterally, and the part beueatli inclosed by the prefrontals 

 particularly wide. The fontanelle iu this region does not appear to 

 have been entirely closed. The surface is here also strongly rugose. 

 The vomer has a T-shaped anterior extremity, which is immediately 

 followed by tsvo transverse parallelogrammic patches of premaxillary 

 brush-teeth in several rows. They are about twice as long as wide and 

 iu contact medially. The anterior nuirgin of the preraaxilla projects 

 their length beyond them, and is perfectly smooth and has a smooth 

 rounded border. The basi-occipital has a subcordate cotylus. In front 

 of the median inferior pit are three groove-pits; the articular face for 

 the posttemporal is opposite the former, and is rugose and has strongly 

 reverted edges. 



Measurements. 



M. 



Diameter occipital articulation 0082 



Diameter base supra-occipitid shield 0130 



Width front above orbits 004:^ 



Length from vomer to premaxilhiry border 0110 



Length of both tooth patches Ol'JO 



Diameter pectoral spine at base . . 0031 



The pectoral spine is serrate on both edges. The base of the dorsal 

 is symmetrical and articulates with its interneural bone by two lateral 

 flat and one convex median anterior condyles, whose surfaces are 

 curiously rugose. The interneural has a rugose median superior keel, 

 which terminates in a point which is received into a pit of the base of 

 the spine ; there is a similar production on the posterior side for a simi- 

 lar purpose. The basis of the spine proper is smaller than that of the 

 pectoral, and is about as wide as deep. 



In a number of fragments of auotlier individual, found together, the 

 basi-occipital has the characters already described. The dentaiy bone 

 is curved inward, and is acute below, widening regularly to the alveolar 

 border. There is no groove on the inner face, while the outer is striate- 

 grooved and has a series of pits along its lower middle. 



Measurements. 



M. 



Diameter occipital articulation 009 



Width alveolar iace 004 



Depth of ramus at middle 003 



* Named for my respected friend Daniel B. Smith, of Germantown, many years priu- 

 cipal of Haverford College, and ;i student and Iovol- of natural sciences. 



