On some Fishes from the Lower and Middle Karroo Beds. 3 



30 rays behind the 1st long ray. There are well-developed fulcra. 

 All the rays are jointed, and all except perhaps the first two long 

 ones are branched. 



The pelvic fin has 27 rays, all jointed, and the posterior rays 

 branched. 



The anal fin is very large. It has 48 rays, of which the first 

 nine are short. All the rays are jointed, and the short anterior rays 

 and the first six of the long rays are unbranched. All the posterior 

 rays are bifurcated. 



The caudal fin is very powerful and deeply bifurcated. The lower 

 lobe is quite as large as the upper. All the rays are branched, but 

 most only bifurcated. 



The scales of the anterior part of the body are rhombic, with 

 feeble transverse irregular ridges and denticulate posterior margins. 

 The posterior scales are unornamented. 



Some very large scales are situated in front of the anal fin, and 

 large ridge scales are also above the root of the tail. 



ATHERSTONIA CAIRNCBOSSI, sp. nov. 



This new species of Atherstonia is founded on the greater part of 

 a fish found by Mr. J. L. Cairncross at Coleskop in 1906, and 

 presented by him to the South African Museum. It was regarded 

 at the time as a small specimen of Atherstonia scutata, S.-W., 

 but on comparing it with undoubted specimens of the type species 

 in the Albany Museum it is seen to be a different species. 



It differs from A. scutata in being relatively shorter and deeper. 

 In A. scutata the length from the clavicle to the base of the tail is 

 about 200 mm., and the greatest depth of the body about 75 mm. ; 

 in this new species the length from the clavicle to the base of 

 the tail is 117 mm., and the greatest depth 57 mm. In other 

 words, the depth of the body in the new species is half the length 

 without the head and tail; in A. scutata the depth is only a little 

 more than ^ the length. 



The dorsal fin has a long base and is powerful. It begins 

 nearer to the clavicle than to the base of the tail, and not as in 

 A. scutata nearer to the tail. The enlarged ridge scales do not 

 strengthen the front of the fin so markedly as in A. scutata, and 

 the fulcra are very rudimentary. There are about 43 rays, which 

 are jointed but not bifurcated. 



The pelvic fin is in front of the dorsal, ending opposite the 

 point where the dorsal begins. It has about 25 jointed rays. 



