The Echinoderm Fauna of fimtth Africa. 317 



P.F. 14380. Cape Hangklip, N.N.E. 31 miles, 95 fms. Gn. s. 

 1 specimen; very young. 



P.F. 18229. Cape Hangklip, N.E. 1/2 E. 5 miles, 60 fms. Gn. m. 

 1 specimen; adult. 



Holotype, South African Museum, no. A 6443. P.F. 18229. 



The growth-stages as revealed by this interesting series are most 

 interesting. The smallest individual has the disk only 3'5 mm. across, 

 and the arms about 18 mm. long; the proportion is thus about the 

 same as in the adult. Conspicuous radial shields about -75 mm. 

 long and -40 mm. wide are present in two adjoining radii but are 

 lacking in the other three; in one of these three the arm is noti- 

 ceably smaller than in the other four radii. There is thus some 

 indication of an earlier reproduction by fission, but none of the other 

 specimens hint at such a possibility. The disk granules are few 

 but relatively large. Most of the arm-segments have only 2 arm- 

 spines and none has more than 3. The genital slits are well 

 developed. 



The next specimen in size is 7 mm. across the disk. Radial 

 shields, 1 mm. long by -50 ram. wide, are distinguishable; they are 

 more or less surrounded by a series of minute granules, but as many 

 disk granules are nearly a millimeter in diameter, they are not very 

 distinct. Some of the basal arm-segments have 4 arm-spines, but 

 those near middle of arm have only 3 and distally only 2. In spec- 

 imens 9 mm. across the disk, there are no radial shields visible; 

 their position is indicated by a group of minute granules ; the ap- 

 pearance is as tho the little granules which surrounded the radical 

 shields had closed in over the shield and buried it. The specimens 

 from off East London are dry and are clasping coral fragments, 

 cidarid spines, etc. ; they are light brownish- white, and the arms are 

 tightly coiled, so their general appearance is quite unlike that of 

 the holotype, at first glance. 



This species is as isolated structurally as it is geographically. 

 The four species of Astrothamnus previously known are all Asiatic ; 

 one from the coast of Oman, two from the East Indies and one 

 from Japan. The South African form is nearest to the Japanese 

 species, echinaceus, so far as can be judged from descriptions and 

 figures but it differs in the presence of numerous oral papillae, in 

 the possession of arm-spines guarding the second tentacle-pore, in 

 having 4-6 arm-spines on the basal arm-segments (instead of only 

 3) and in the liner and more even granulation of the oral surface. 

 In the possession of oral papillae, papiilatus resembles bellator from 

 the Sulu archipelago, but the differences in the granulation of the 



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