REMARKS ON BATHYGNATHUS BOREALIS. 451 



cult from lines of fracture traversing the surface, as well as from more marked 

 mutilation of the specimen. An oblique line or fissure, a fourth of an inch in 

 advance §f the fracture, following the course of the larger tooth, partially only and 

 not well represented in the plate, may indicate the suture between the maxilla 

 and premaxilla. Another line, rather more than an inch below the upper oblique 

 border of the bone, may indicate the nasomaxillary suture. 



If the natural condition of the portion of the face is preserved in the fossil, the 

 bone as a whole expresses a remarkable proportionate depth and narrowness or 

 lateral compression, though the latter may, perhaps, be in a measure due to some 

 crushing. The side of the face presents a broad almost vertical surface, nearly flat 

 over the alveolar parapet, and forming a wide concavity above. 



No portion of the orbital margin is perceptible in the fossil, and the limit of 

 the maxilla behind and below is attenuated to the thinness of paper where it artic- 

 ulated with the malar. 



The surface of the face is marked fore and aft by many vascular grooves, 

 though no conspicuous vascular foramina are observed. The upper limit of the 

 fossil is convex, and formed apparently by the nasal bone, which is from a line to 

 a line and a half thick. 



Prof. Owen points out a space, marked n in his figure, which he suspects to 

 be "evidence of an external nostril." This is a mistake, and as seen in the plate 

 accompanying my paper is a vacuity left on the matrix by the breaking away of 

 a portion of bone. In advance and below this, however, in the same plate, there 

 may be observed a circular, funnel-like space, partly inclosed by the bone with a 

 thickened, rounded border, which may fairly be suspected of being the external 

 nasal orifice. 



In conclusion, while it appears to me that the fossil referred to Bathygnathus 

 has little afiinity with Lycosaurus and other representatives of the Theriodonts, its 

 more intimate relationships are with Megalosaurus and Teratosaurus. 



