Cope.] OUb [April 5, 



ropelicus, the following characteristic marks appear : The tooth-line di- 

 verges much more strongly inwards from the maxillary border in the B. 

 latibuccatus, leaving a wide groove between the two. This groove is 

 separated by a narrow horizontal partition from a corresponding one of the 

 superior face of the same element, and its surface is longitudinally rough- 

 ened. The teeth aie closely placed, and the series turns with the anterior 

 extremity of the jaw, abruptly inwards. The transverse diameter of the 

 teeth lessens to just posterior to the point of curvature, so that their section 

 is nearly round ; at and anterior to the curve, the wide transverse diameter 

 is resumed, the last alveolus preserved making an angle of 45° with those 

 in the posterior part of the jaw. The external surface of the maxillary 

 hone is roughened, as is also the case in the D. sideropelicus, with coarser 

 and finer irregular impressions, fossae and grooves. 



Measurements. M. 



Width of jaw at ninth tooth from curve 036 



Width of ninth tooth from curve Oil 



" "fourth " " " 006 



" " tooth at curve 008 



" " third tooth anterior to curve 010 



" " jaw at curve , 019 



Elevation of alveolar part of jaw 018 



Three teeth in 015 



There are other fragments of jaws referable to Diadectes whose specific 

 reference is uncertain. 



Bolosatjeus striatus. Gen. et. sp. nov. 



Char. (ilen. Teeth fixed in shallow alveoli, and with the crowns ex- 

 panded transversely to the axis of the jaws. The crowns swollen at the 

 base, and with low apex, divided vertically into tw T o equal portions. The 

 postero-internal half in the maxillary series is low and horizontal ; the 

 antero-external portion forms a curved cusp, which has a semicircular sec- 

 tion. The teeth of the lower jaw are similar, but the relative positions of 

 the ledge and cusp are reversed. Anterior teeth of superior series com- 

 posed of external cusp and internal ledge. No enlarged canine or incisor 

 teeth. Bones of face not sculptured. 



This genus is represented by a good many remains, which include some 

 partially complete crania. These show that there is no quadratojugal arch, 

 and that the quadrate is of the flat character of that of the Anomodontia, 

 and was probably immovable. The orbit is complete behind, and there is 

 a strong squamosal arch. The vertebrae are amphicoelous, and probably 

 notochordal. The neural arches are freely articulated with the centrum, 

 and the zygapophyses and neural spine are well developed. 



The vertebrae resemble those of Lysorophus* CCope) from the Illinois 

 Permian, but they do not display the deep longitudinal fossae of that 

 genus. 



* Proceed. Amur, Philos. Soc. 1877, p. 1S7. 



