266 Annals of the South African Museum. 



joining the tips of the tail is 100 mm., and the greatest depth from 

 the highest point of the back to the base of the pelvic fin is 72 mm. 



CLEITHEOLEPIS MINOR, n. sp. 



The large majority of the specimens of Cleithrolepis are only 

 about two-thirds the size of the type specimen of C. extoni. For 

 some time I was inclined to consider all these as merely young 

 specimens, but on careful examination they reveal sufficient points 

 of difference to justify them being placed in a distinct species. In 

 C. extoni the depth of the head is less than one-third the depth 

 of the body ; in C. minor it is almost half. In C. extoni the line of 

 the back forms an obtuse angle a little nearer the front of the dorsal 

 fin than the occiput ; in C. minor the line of the back forms a gentle 

 curve. In the former species the cranial bones and the scales are 

 covered with tubercles ; in the latter the tubercles are very slightly 

 developed on the opercular and other cranial bones, and even of the 

 scales they are relatively much smaller than in C. extoni. The tail 

 in C. minor is much more deeply bifurcated, and the dorsal and anal 

 fins are much smaller and do not extend so near to the base of 

 the tail. 



The largest specimen of C. minor measures 72 mm. in greatest 

 length and 43 mm. across the body to the base of the pelvic fin. 

 The dorsal fin has about 18 rays, the anal 12 or 13. The caudal 

 fin has about 30 rays. 



HYDROPESSUM KANNEMEYERI, g. et sp. nov. 



In Kannemeyer's collection there are two specimens of this 

 beautiful little deep-bodied ganoid, and unfortunately both are 

 imperfect. One specimen exhibits the upper two-thirds of the body 

 including most of the head and the tail ; the other shows the greater 

 part of the body, but has very little of the head. 



Though allied to Cleithrolepis, this genus differs in that it is 

 extended up so that the edge of the dorsum makes nearly a right 

 angle, and the ventral region is probably similarly produced, so that 

 excluding the tail the body is apparently deeper than long. There 

 is the further marked difference in that the dorsal fin begins at the 

 upper angle of the back, and is a short fin with a very long base. 

 In general appearance Hydropessum is thus strikingly like Cheirodus, 

 but there is not the slightest doubt that it does not belong to the 

 Platysomidas, but is a near ally of Cleithrolepis. 



The larger of the two specimens measures from the snout to a 



