316 Annals of the South African Museum. 



Key to the South African Species of Gorijonocephalidae. 



Arms simple ...... Astrothamnus papillatus. 



Arms much-branched. 



Nearly all tentacle-pores before first fork of arms guarded by minute arm- 

 spines ...... Gorgonocephalus chilensis. 



No arm-spines on basal tentacle-pores* . . . Astrocladus euryale. 



ASTROTHAMNUS PAPILLATUS **, sp. nov. 

 Plate XX. Figs. 5, 6. 



Disk 18 mm. across; arms rather more than 100 mm. long. Disk 

 slightly tumid, the ridges formed by the radial shields wide (3 mm. 

 distally) and not conspicuous, though the interradial depressed groove 

 is fairly well marked, thus defining clearly the radial wedges. Whole 

 upper surface of disk covered by coarse granules, the largest nearly 

 a millimeter in diameter; they are well-spaced but there are scattered 

 among them smaller granules with which they intergrade; the larger 

 granules usually are rough or even prickly on the top. Arms 4 mm. 

 in diameter at base but tapering rather rapidly to the attenuate tip. 

 From their very base the arms are encircled by alternating bands 

 of fine and coarse granules; the former bear numerous minute hooks 

 and booklets while the latter are more or less nearly smooth. There 

 are two or three (rarely more) series of granules in each band ; 

 when more than two, the marginal series are the coarsest. 



Interbrachial areas below rather small and covered with a coat of 

 very fine granules, abruptly and conspicuously smaller than those at 

 the margin of the disk. Genital slits fully 3 mm. long. Surface of 

 jaws and mouth frame and lower surface of arms as well, covered 

 by a rather uniform coat of fine granules, coarsest on the interradial 

 portions of the mouth-frame. Teeth, tooth-papillae and oral papillae 

 present, spiniform and similar except that the teeth are much the 

 largest and the distal oral papillae are smallest. First pair of ten- 

 tacle-pores of arm naked and small, nearer together than the fol- 

 lowing; second pair with 2 short, slightly thorny arm-spines; third 

 pair with 3 or 4 ; following pairs .with 4 or usually 5 and very rarely 6. 

 Colour, dried from alcohol, light yellow-brown. 



P.F. 12872. East London, N. 15 miles, 310 fms. M. 9 specimens; 

 adult and young. 



In specimens more than 15 mm. across disk. Young specimens may have 

 minute arm-spines on all but the first pair of pores. Such specimens may be 

 distinguished from young Q. chilensis by the absence of granules on the disk and 

 the generally smooth appearance of both surfaces of the body. 

 ** papillatus = having papillae, in reference to the numerous oral papillae. 



