Cope .J VO A [March 16, 



short and narrow maxillary bone. Two ilia accompanying the cranium 

 have the form of those of the Clepsydropidai, and differ entirely from those 

 of the Diadectidce. On the other hand, the foramen magnum is wide, and 

 the exoccipitals present two articular facets downwards as in the latter family. 

 It is possible that the genus should be referred to the Bolosauridce, which is 

 in dentition intermediate between the Glepsydropidce and Diadectidce. 



A femur, which is included in the lot of specimens, has a wide head with- 

 out trochanters, convex in the plane of the distal condyles and flat in the 

 direction at right angles to it. There is a huge trochanteric fossa extend- 

 ing from the head two-fifths the length to the condyles, bordered by a ridge 

 on each side. The condyles present in the same direction as the fossa pos- 

 teriorly. They are separated by a deep anterior and posterior emargina- 

 tion. Their anterior edges overhang the condylar articular surfaces, 

 making acute angles with them. One of the articular surfaces is smaller, 

 is anteroposteriorly extended, and has a convex ectad, and concave entad 

 border. The other surface is also anteroposterior, reaching further distad, 

 but not so far proximad as the other. Its area is greater than that of the 

 other, and it is deeply notched by the entering surface of the bone ectad 

 and proximad. It is then contracted into a Wide isthmus, and the lateral 

 grooves which produce this isthmus are overhung by the expansion of the 

 anterior face. The anterior face of the femur is without ridges or pro- 

 cesses. 



The condition of the specimen is such that the composition of the skull 

 may be readily made out. The postfrontal bones are large, and form the 

 superior border of the orbit. At the front of the orbit they reach the pre- 

 fontal, thus excluding the frontal. The parietal bones are wider than the 

 frontals, and are bounded laterally by the postfrontals and the squamosals 

 and by an element between the squamosal and exoccipital, which occu- 

 pies the position of the intercalareof the Stegocephali. Below this bone, on 

 the inner side of the suspensorium, is the probable prootic. The squamo- 

 sal, or an element which I cannot distinguish from that bone, extends to 

 the condyle of the quadrate, concealing that bone from view from exter- 

 nally. The quadrate is short, and thins out rapidly upwards, being closely 

 united with the squamosal. Its condyle is set at an angle of 45° with the 

 axes of the skull, and consists' of one flat and one convex surfaces, con- 

 tinuous but forming a deep angle together. Exterior to the exoccipital, 

 and interno-inferior to the intercalare, is a small distinct element, appar- 

 ently in the position of an opisthotic or external occipital. 



The excavatioh for the auditory apparatus appears to be in the exoccip- 

 ital. It is almost entirely filled by what I suppose to be a large stapes. 

 This bone is in shape like a compressed flask, with the head directed in- 

 wards and forwards, and its inferior edge produced into a prominent keel, 

 which is produced into a point below, and free from the neck of the flask. 

 The head is truncate, and is separated from the internal cranial wall by a 

 narrow interspace. Its external extremity is not absolutely perfect in the 

 specimen, but does not appear to have extended in an ossified condition be- 



ns**. 



