258 Annals of the South African Museum. 



branched distally. Small fulcra are present in front. The pelvic 

 fin is badly preserved. The dorsal fin is almost wholly in front of 

 the anal. It has about 25 rays. I cannot detect any fulcra in front 

 of it, but the condition of the fin is somewhat unsatisfactory. 



The caudal fin is deeply bifurcated, the upper lobe being the 

 longer. Along the top of the upper lobe is a row of specialised ridge 

 scales, but they are not much larger than the other scales of the tail. 

 All the rays of the caudal fin are articulated and branched. 



The scales of the side of the body are about as deep as broad. 

 The lower and posterior margins are both straight, but the posterior 

 one is distinctly serrated in the scales of the anterior half of the 

 body. From the serrations on some of the scales there run forwards 

 for a short distance a few feeble ridges. 



While there may still be some doubt as to the genus of this species 

 it can confidently be stated that it cannot be referred to Dictyopyge. 

 Nor do I think it can be placed in the genus Bhadinichthys, which is 

 characterised by having the suspensorium very oblique. Though 

 the fin rays differ a little from those of Helichthys browni, the 

 general structure of the skull so far as known is so similar that it 

 seems advisable to place this species in the same genus as the other. 



HELICHTHYS TENUIS, n. sp. 



This very well-marked species is represented by only one 

 specimen, and that a badly preserved. The fish is fairly com- 

 plete, but it is so much weathered that little remains beyond the 

 impression. 



The complete fish probably measures 90 mm., and the greatest 

 depth is 16 mm. The head measures 16 mm. Though in general 

 structure it agrees with H. browni, and most probably belongs to the 

 same genus, it differs from that species in being more slender, in 

 having the dorsal and anal fins much smaller, and in having the 

 peduncle of the tail much longer. 



The head agrees fairly well with that of H. broivni, but is longer 

 in proportion to the height. The pectoral fin is smaller than in the 

 type species and has apparently 18 rays. The dorsal fin is also 

 smaller, but has a larger number of very delicate rays apparently 

 30. No distinct fulcra can be detected. The fin is situated only 

 very slightly in front of the anal. Like the dorsal the anal fin has 

 many delicate rays probably 36. The caudal fin is not preserved, 

 but the distance from the posterior part of the anal to the front of 

 the caudal fin is at least 13 mm. In the type of H. broivni the 

 corresponding distance is only 5 mm. 



