Fossil Fishes of the Upper Karroo Beds of South Africa. 257 



and unbrancbed. Fulcral bones are -present on tbe front of the 

 distal balf of the fin. 



The caudal fin is lost in the type specimen, but from other 

 specimens it is seen to agree closely with the caudal of the 

 following species. 



Squamation. The scales on the sides are rhomboidal, with the 

 inferior borders somewhat convex and the posterior borders nearly 

 straight and smooth. The posterior angle is slightly produced. The 

 scales on the abdominal region are narrower and closely imbricated. 

 All the scales are practically smooth. 



While most of the specimens are of the same size as the type, 

 one which I cannot distinguish specifically is considerably larger, 

 measuring 140 mm. in length. It is not w T ell preserved and may 

 prove to be distinct, but so far as can be seen there is no distinct 

 difference except in size from the typical H. broivni. 



The genus Helichthys seems well differentiated from any other 

 previously described. The other genera of Palaeoniscids with the 

 suspensorium nearly vertical are Canobius, Gonatodus, Drydenius, 

 Amblypterus, and Eurylepis, and of these only Amblypterus seems 

 to have any close affinity. Further, all are Carboniferous genera 

 except Amblypterus, which is also found in the Permian Age. From 

 Amblypterus, Helichthys differs in having a feebler tail, and in having 

 the fin rays not or only slightly branched. 



HELICHTHYS DRAPEKI, Smith-Woodward. 



In 1893 Smith-Woodward (8) described under the name 

 Dictyopyge (?) Draperi a fossil fish from Eouxville, O.E.C. The 

 type specimen has lost the tail, and Smith- Woodward was in doubt 

 whether to regard the species as a Palssoniscid or a Catopterid, but 

 provisionally placed it in the genus Dictyopyge. In Mr. Brown's 

 collection is a fairly well-preserved specimen which shows that the 

 fish is undoubtedly a Palaeoniscid and enables me to add to the 

 original description. 



Mr. Brown's specimen measures 133 mm. in length and 28 mm. 

 in depth, while the head measures 27 mm. in length. The head is 

 not very well preserved, but the specimen shows that the suspen- 

 sorium is, as in Helichthys broivni, nearly verticle. The mandible is 

 long and slender, as is also the anterior part of the maxilla. The 

 opercular bones are large and smooth, but the anterior frontal region 

 has a considerable amount of rugose ornament. The shoulder girdle 

 is not well preserved, but has apparently little or no ornamentation. 



The pectoral fin has 16 rays articulated in the distal half and 



