246 REPORT OF NATIONAL MUSEUM, 1898. 



Tongue arrow-shaped, slightly notched at tip; where it is free as at the 

 sides, the tip beneath with two ovate disks. Palatine teeth. Cheek 

 teeth compressed, with three-lobed crown behind; conical anteriorly; 

 the bases apparently in a shallow groove ; the space between the bases 

 of the teeth tilled up partly with bone. 



Osteology. — The skeletons of the two most abundant species are before 

 me, namely, the C.coUaris Holbrook and G. unslizenii Bairdand-Girard, 

 The following description includes both, and if any differences between 

 the two exist, they are mentioned. 



The premaxillary has a long spine above and a concave border behind 

 on the palate, from which projects forward a pair of juxtaposed proc- 

 esses which together form a button-like process which has an anterior 

 free border. The nasals are wide and shortened by the removal of 

 their anterior border on account of the large size and partly vertical 

 direction of the nostrils. Frontal single, narrow ; pineal foramen touch- 

 ing coronal suture, in the frontal bone in (J. collaris and in the parietal 

 in C. unslizenii. Prefrontal large, with a prominent preocular boss, not 

 extending posteriorly over the orbit. Lachrymal small, in line with and 

 touching the jugal. Postfrontal wanting; its place taken by a process 

 of the frontal. Postorbital large, uniting exteriorly with jugal and 

 supratemporal. Parietoquadrate arch elevated; supraoccipital bone 

 loosely articulated, not distinct from exoccipital. Quadrate with rather 

 flat conchs, the external the larger, and with straight external border. 

 Postoptics not reaching frontal, curved, with short posterior branch. 

 Petrosal with prominent subforaminal jiortion, which has an open groove 

 looking downward. Vomers short and wide, not sej)arated by a groove. 

 Palatines flat, with short maxillary process. Pterygoids rather nar- 

 rowed by the large palatine foramina; posterior part grooved and 

 receiving basipterygoid processes. Ectopterygoids depressed inter- 

 nally. Epipterygoid originating behind ectopterygoid process, and 

 reaching parietal without contact with petrosal. Presphenoid rudi- 

 mental; sphenoid and basioccipital confluent. Occipital condyle j/lain, 

 with exoccipital elements not distinct. The fenestra ovalis and foramen 

 of eighth nerve sunk in deep fossie. 



In the mandible the terminal part of Meckel's cartilage is exposed. 

 The coronoid has no extension on the external face, and extends a short 

 distance forward on the inner face. The splenial is rather elongate, 

 and extends anterior to the splenial foramen. The dentary extends to 

 the line of the posterior border of the coronoid above and of its ante- 

 rior border blow. In old individuals the surangular and articular are 

 fused. The angle is pinched, and sends inward a horizontal process 

 similar to its posterior process. 



In the hyoid apparatus the ceratobranchials of the second pair are 

 closely appressed, thus supporting a median gular angle. The hypo- 

 hyals are moderately long, and they join by their extremities the cera- 

 tohyals, which have no expansions and are of only moderate length. 



