386 THE VOYAGE OF H.M.S. CHALLENGER. 



in the larger groups in the interradial area. In some examples the spinelets are less 

 robust, and there are fully twice as many in a group. 



The madreporiform body, which is small, is situated nearer the centre than midway 

 between that poiut and the margin. It has a papillose rather than a striated appearance, 

 in consequence of the frequent division of the intervening ridges. Several large plates 

 with spinelets surround the margin. 



Colour in alcohol, an ashy grey or greyish white. 



Young Phase. — There is a small example from the same locality, which I have 

 no hesitation in referring to the same species. Its measurements are B = 20 mm., 

 r=7'5 mm. The outer part of the rays is occupied only by large diamond-shaped 

 plates with a pore at the angles. At the base of the rays and on the disk small plates 

 are intercalated, and these usually have a pore at each side ; the larger plates are more 

 elongate transversely, and there is occasionally a tendency to assume the crescent shape, 

 which appears, however, to be mainly caused by the slight arching of the group of 

 spinelets borne on the plates. This character produces more or less of the Asterina 

 facies, and leads to the supposition that Patiria may perhaps be traced phylogenetically 

 to an Asterina ancestor. The armature of the adambulacral plates and the spinulation of 

 the actinal intermediate plates, as well as the character of both, accord exactly with the 

 adult form described above. 



Locality. — Simon's Bay, Cape of Good Hope. Shallow water. 



Remarks. — This species resembles in many respects Patiria crassa, Gray, of which 

 it is probably the South-African representative. Patiria bellula may be distinguished by 

 the comparatively shorter rays, which are broader at the base and more tapering, and by 

 the character of the adambulacral armature, which in Patiria bellula consists of two 

 series composed of three or four spines in each, whereas in Patiria crassa there are at 

 least three series, composed of five to seven spinelets in each. Furthermore in Patiria 

 bellula these spinelets, as well as the spinelets on the actinal intermediate plates, are 

 much more robust and altogether stronger in character than in Patiria crassa. This is 

 specially noticeable in the case of the actinal intermediate plates. 



Genus Nepanthia, Gray. 



Nepanthia (liars), Gray, Ann. and Mag. Nat. Hist., 1840, vol. vi., p. 287. 



Asterina (subgenus Nepanthia), Perrier, Re>is. Stell. Mus., 1876, p. 320 (Archives de Zool. expe>., 

 t. v. p. 240). 



Gray included two species in his genus Nepanthia, one of which is a Chsetaster. 

 This was pointed out by Perrier, who thus limited the genus, and added at the same time 

 two new species founded on specimens preserved in the British Museum. Perrier, 1 at 

 1 ReVis. StelL Mus., pp. 295, 320 (Archives de Zool. exp'er., t. v. pp. 215, 240). 



