252 Annals of the South African Museum. 



Eouxville district, O.E.C. ; (3) a few specimens obtained by Mr. 

 E. A. Albertyn from near Eouxville, and now in the Victoria College 

 Museum, Steilenbosch ; and (4) the very fine specimens of Semi- 

 notus capensis in the South African Museum obtained from Ficksburg 

 by Chief Justice de Villiers. 



HYBODUS AFEICANUS, n. sp. 



In Mr. Brown's collection there are numerous fish spines, and 

 one specimen shows much of the shagreen of the little shark with 

 many teeth, but as in Dr. Kannemeyer's collection there is an 

 almost complete specimen, though of a smaller animal than Mr. 

 Brown's, I shall take as the type this specimen which Dr. Kanne- 

 meyer has presented to the South African Museum. 



The specimen measures 230 mm. in length. The head is not 

 well preserved, but the jaw T s are fairly distinct. One of the cephalic 

 spines is preserved very similar in general shape to those figured by 

 Smith Woodward in H. mcdius (1). The quadrate portion of the 

 upper jaw is deep ; the whole lower jaw apparently rather slender. 

 If the most anterior part where shagreen can be detected is really 

 the rostrum, then the mouth is situated well forward. The upper 

 jaw is about 20 mm. in length. At about 43 mm. behind the sup- 

 posed rostrum is a large shoulder girdle which, as preserved, is 

 nearly 30 mm. in length and 8 mm. wide in its broadest part. 

 Immediately above it is situated the base of the anterior spine. 

 Unfortunately in the type specimen neither of the spines is well 

 preserved. Behind the lower part of the girdle is a small flat area, 

 which probably represents part of the pectoral fin. The anterior 

 spine is situated about 46 mm. from the rostrum, and the second 

 spine is 110 mm. behind the first. At a point 124 mm. behind the 

 rostrum on the ventral side is a structure which probably represents 

 the pelvic fin with a large clasper. It is, however, too indefinite to 

 say anything of the detailed structure. Comparatively little of the 

 axial skeleton can be made out. In the caudal region a number of 

 hgemal spines are very clearly shown, and a large number of neural 

 spines are indistinctly seen in the middle region of the body. In 

 the abdominal region a little behind the shoulder girdle are indica- 

 tions of some curved slender structures suggestive of ribs. Perhaps 

 they may be due to intermuscular septa. 



One specimen obtained by Dr. Kannemeyer shows a dorsal spine 

 and fin in splendid preservation. The specimen is too imperfect to 

 show whether it is an anterior or posterior fin. The spine shows 

 the posterior denticles and the ridging characteristic of Hybodus. 



