The Echinoderm Fauna of South Africa. 337 



P.F. 13225. Cove Rock, N. W. 3 / 4 W., 13 miles, 80130 fms. 

 Crl. and r. 2 specimens; adult. 



OPHIOTHRIX FRAGILIS. 



Asterias fragilis Abildgaard, 1789. In Miiller's Zool. Dan., vol. 3, 



p. 28; pi. XCVIII. 



Ophiothrix fragilis Diiben and Koren, 1846. Kongl. Vet.-Akad. 



Handl. f. 1844, p. 238. 



Some specimens of a coarse Ophiothrix from Saldanha Bay per- 

 plexed me greatly until I found that Koehler had recorded this 

 European species from that very place. Comparison of these speci- 

 mens with some of equal size of fragilis from Heligoland shows 

 that they may without impropriety be referred to that species, although 

 they do not agree in all details. They approach so nearly to some 

 specimens of triglochis, indeed, that one wonders whether fragilis 

 and triglochis are really distinct. The only difference between the 

 two species is that in typical triglochis there are no disk-spinelets 

 among the stumps and the radial shields are more or less well 

 covered by the latter. But as will be pointed out below, the pre- 

 sent collection shows that triglochis is a very variable species and 

 it may be that it will be best to treat it merely as a southern 

 variety of fragilis. 



As pointed out in the key above, the Ophiothrix from Saldanha 

 Bay has very large, bare radial shields and the rest of the disk is 

 rather densely covered with long, stout, thorny spinelets. The gene- 

 ral colour is dingy white on the disk, with both disk-spinelets and 

 arm-spines pale brown; the radial shields have narrow dull red 

 margins and the upper arm-plates are a mixture of dull reddish and 

 dingy white. 



P.F. 14905. Saldanha Bay, Cape Colony, 10 fms. S. and mussel- 

 beds. 6 specimens; adult. 



OPHIOTHRIX TRIGLOCHIS. 



Miiller and Troschel, 1842. Sys. Ast., p. Hi. Koehler, 1904. 

 Mem. Soc. Zool. France, vol. 17, p. 81, iigs. 41 45. 



The PIETER FAURE collection shows clearly that this is the com- 

 mon Ophiothrix of South Africa. There are 170 specimens from 23 

 stations, and while they show great diversity I feel no hesitation in 

 referring them all to triglochis. The smallest is only 2'5 mm. 

 across the disk and shows the primordial central plate very plainly. 



