412 Mr. A. S. Woodward on 



arrangement of the fins are precisely as in the larger typical 

 specimens of P. cataphractus. The pelvic fins are about as 

 large as the pectorals, though with fewer rays, the former 

 comprising only 8, while the latter exhibit approximately 14 

 rays. The dorsal fin is very imperfect, but clearly shows 14 

 or 15 raysj while the anal is relatively small, but also com- 

 prises about 14 rays. 



8. Spaniodon hahelensis, J. W. Davis, loc. cit. p. 591, 

 pi. xxxiv. fig, 4. [= Ckaritosomus hakelensis ^ 



In the type specimen of this species the long and low 

 cranium is exhibited chiefly in longitudinal section, and the 

 stout parasphenoid is sliglitly arched, the concavity being 

 downwards. Remains of the delicate and toothless pterygo- 

 quadrate arcade are seen, proving the mandibular suspen- 

 sorium to be much inclined forwards, with the mandibular 

 articulation below the anterior margin of the orbit. The 

 mandible, shown chiefly in impression, is remarkably short 

 and deep, the height of the coronoid region apparently 

 equalling nearly two thirds of the total length of the jaw ; 

 and although the impression may be imperfect in front, it is 

 clear that the gape of the mouth must have been very small. 

 Below the end of the rostrum and above the mandible there 

 is a large stout arched bone, which must have been either 

 maxilla or premaxilla, and its form specially recalls the 

 maxilla of the Gonorhynchidai Below and behind the 

 mandibular articulation an obscure fragment of bone bears a 

 cluster of smooth, rounded, grinding teeth of unequal and 

 irregular size; and there seem to be traces of simih'xr teeth 

 obscured by the pterygoid bones immediately beneath the 

 parasphenoid. The opercular apparatus is too imperfect for 

 description, and tliere are only fragments of a few broad 

 branchiostegal rays. The axial skeleton of the trunk is well 

 exposed and comprises about 42 vertebrae, of which 14 are 

 caudal. The centia are much constricted, about as long as 

 deep, with very stout neural arches throughout the column 

 and similar hiemal arches in the caudal region. All the 

 neural spines seem to be firmly fused with tiieir supporting 

 arches, and the four foremost spines in the abdominal region 

 are expanded into distally truncated laminae, while a few of 

 the succeeding spines are also a little broad. The ribs are 

 very delicate and do not completely encircle the abdominal 

 cavity. The neural and ha3mal arches in the caudal region 

 are slender, except close to the base of the caudal fin, where 

 they become longer and stouter. The ha^mals do not appear 

 to fuse into a hypural bone at the base of the caudal fin. 



