Cope.] ^4 J [May 6, 



convex, rises but little above the level of the dentary. The dentary is 

 produced below it. On the inner side is seen a large splenial foramen, 

 from which extends anteriorly a narrow strip, the splenial. The other 

 borders of the foramen are formed by a large laminiform bone, the oper- 

 cular of Cuvier, which extends to the superior border of the ramus, cut- 

 ting off the dentary posteriorly. It is apparently homologous with the 

 inferior anterior part of the coronoid. For the remaining parts of the 

 mandibular ramus see the description of the second specimen. The exter- 

 nal face of the dentary is roughened and presents foramina which are 

 most numerous anteriorly, where they are connected by shallow grooves, 

 like the rims between the holes of small Mammalia. Opposite each tooth 

 is one or two shallow vertical grooves. 



The teeth have the usual Megalosaurian form and have long roots sunk 

 in very deep alveoli. There are eleven present in the maxillary bone, of 

 which the terminal ones are rapidly reduced in dimensions. Fourteen 

 teeth in the dentary bone which diminish in size at the posterior end of 

 the series. The premaxillary teeth are lost, but none of those in the an- 

 terior part of the dentary bone have the incisor-like character of those of 

 the genus Amblypodon of Leidy. The first tooth of the dentary is smaller 

 than the second, and both have more convex external faces than the teeth 

 which succeed them. 



Measurements of Skull iVo. 1. 



MM. 



Total length of specimen 600 



Lengtii (axial) to front border of preorbital foramen 140 



Length to anterior border of orbit 215 



Length to posterior border of orbit 385 



Vertical diameter of orbit 120 



Vertical diameter of skull at middle of orbit 180 



Width of front at middle of orbit 80 



Depth of dentary at posterior end of symphysis 90 



Depth of dentary at end of dental series 127 



Length of dental series 320 



Length of dentary bone above 390 



Length of sixth tooth above alveolus 57 



Width of sixth tooth at alveolus 22 



In the second skull the only part of the superior portion remaining is the 

 brain case, and this is distorted by pressure which has forced it to the left 

 side of the middle line. The postorbital region and the arches are gone. 

 The occipital appears to be continuous and subhorizoutal and is obtusely 

 angulate medially above. The basioccipital is vertical as in the crocodiles 

 proper, and the brain case is closed in front of the petrosal in much the 

 same way, with thin ossifications. The foramen magnum is small, as is 

 also the transversely oval occipital condyle, which looks directly posteri- 

 orly, and not downwards. On each side of the basioccipital are two large 



