Fossil Fishes of the Upper Karroo Beds of South Africa. 267 



line joining the tips of the tail 62 mm., and the greatest depth of the 

 body is probably about 52 mm. 



The cranial sutures are not distinctly seen for the most part, but 

 there seems to be a fairly close resemblance between the general 

 structure of the head in this genus and Cleithrolepis. The operculum 

 and suboperculum appear to differ only in the operculum being 

 perhaps rather smaller relatively. The preoperculum is even rather 

 larger than in Cleithrolepis, and as in that genus a sensory canal 

 runs down its posterior side. The circumorbitals are small. The 

 frontal is large, and the maxilla short. 



The dorsal fin is composed of at least 21 short rays, and extends 

 from the dorsal angle about two-thirds down the posterior dorsal slope. 

 A few small fulcra lie in front, but the rays are not sufficiently well 

 preserved to show whether they are bifurcated and articulated. The 

 caudal fin is deeply bifurcated, the rays of the upper and lower lobes 

 being powerful, those of the middle region feeble. The tail is brevi- 

 heterocercal. 



The scales are rather larger than in Cleithrolepis, and differ in 

 being ornamented not with tubercles, but with numerous small short 

 ridges of ganoine which run vertically and are very irregularly 

 arranged. The cranial bones are scarcely at all ornamented. 



Of previously described ganoids Cleithrolepis seems to be the 

 nearest ally of Hydropessum. Dapedius has a somewhat similarly 

 extended dorsal fin, but the cranial structure is very different in the 

 two. ^Etheolopis differs in the remarkable developments of the 

 fins and tail. 



PHOLIDOPHORUS BROWNI, n. sp. 



In Mr. Brown's collection there are two specimens of a small 

 species of Plwlidopliorus and in Dr. Kannemeyer's two imperfect 

 specimens of a second species, also apparently of the same genus. 



The smaller of the two species, which I am naming after Mr. 

 Brown, measures 74 mm. in length and 15 mm. deep at the pelvic 

 fin. The front of the dorsal fin is situated exactly midway between 

 the snout and end of the tail, and is only a short distance behind the 

 front of the pelvic fin. The head with opercular apparatus measures 

 about 14-15 mm. 



The head is not well preserved in either specimen. The maxilla 

 is slender in front and fairly deep behind. It bears about 14 elon- 

 gated conical teeth, which cannot be described as in the typical 

 Pholidophorus as " minute." Behind and above the posterior end 

 of the maxilla is a large flat bone, or possibly two bones, which must 



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