640 GEOLOGICAL SURVEY OF THE TERRITOEIES. 



Another pectoral spine is larger ; diameter at base, .010. 



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



Bhineastes calvus, Cope, sp. nov. 



Eepresented by numerous specimens, including most parts of the cra- 

 nium, spines, &c. 



One of these shows the supra-occipital production to have the form 

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

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

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

 mences. The cranial rug£e are lines parallel to the fontanelle, which 

 diverge to the margins of the occipital prolongation, and are frequently 

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

 expanded laterally, and the part beneath inclosed by the prefrontals 

 particularly wide. The fontanelle in 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 two transverse parallelogram mic j)atches of premaxillary 

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

 in contact medially. The anterior margin of the premaxilla 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 OQcipital articulation -. 008-3 



Diameter base supra-occipital shield 0130 



Width front above orbits 0043 



Length from vomer to premaxillary border 0110 



Length of both tooth patches 0120 



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 

 fiat and one convex median anterior condyles, whose surfaces are 

 curiously rugose. The interneural hav§ 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 another individual, found together, the 

 basi-occipital has the characters already described. The deutary 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. 



Measuremenis. 



M. 



Diameter occipital articulation 009 



Width alveolar face • 004 



Depth of ramus at middle 008 



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

 cipal of Haverford College, and a student and lover of natural sciences. 



