REPORT ON THE ECHINOIDEA. 85 



Asthenosoma varium, aucl as Grube said nothing of the lajjping of the coronal plates. 

 It was only on seeing the original specimen at Breslau that I recognised the identity 

 of the genera. At that time (1870) Professor Grube was kind enough to give me a few 

 spines of this species, and on comparing them subsequently with those of the species 

 called here Asthenosoma gruhii, there seemed to exist sufficient difierences in. them, and 

 more especially in the greater size of the primary tubercles of the actiual surface (of 

 which Professor Grube had sent me a cbawing), to warrant me in separating these species 

 for the present. Grube's specimen is much smaller than the specimens collected by the 

 Challenger, so that it may yet turn out that the diflferences existing between our 

 specimens are merely due to age. The perforation of the tubercles of the abactinal 

 surface is so small that it could not be represented on the natural size drawing of 

 Plate XVII. fig. 2. It was, however, unfortunately omitted on the figure of the actinal 

 side (PL XVII. fig. 1). It is shown on the enlarged figures (PL XVII. figs. 5, 6). The 

 locality of Grube's specimen was not definitely known ; as it came from Salmin, who had 

 at the time of its pui'chase extensive dealings with the Philippine Islands, it undoubt- 

 edly came from the Eastern Seas of China or that neighbourhood. The specimens of the 

 Challenger aU coming from such a shallow depth as ten fathoms it is quite possible that 

 this species may be a littoral one, or at any rate that it lives in comparatively shallow 

 water. In the species of Asthenosoma, judging from the single smaller specimen of 

 Asthenosoma gruhii and from those of Asthenosoma j^ellucidum, the changes due to growth 

 do not seem to be as marked as in Phormosoma. The smallest specimen oi Asthenosoma 

 gruhii (measuring 115 mm.) already showed the principal specific characters of the adult 

 (183 mm. in diameter), the only important difi"erences being such as are readily accounted 

 for by the size of the specimens. The few spines left on the abactinal surface of this 

 smaller specimen show that the peculiar sheathed spines so characteristic of this species 

 already exist in specimens of a comparatively small size. 

 Samboangan ; 10 fathoms. 



* Asthenosoma pellucidum{^\.XS[lll. figs. 1-6; PL XVIII.'' figs. 14-17; PL XIX. 

 figs. 1-6 ; PL XXXVIII. fig. 6 ; PL XL. figs. 39-42). 



Asthenosoma pellucida} A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 200. 



In this species of Asthenosoma the primary tubercles form a prominent vertical row 

 in the interambulacral area adjoining the poriferous zone, the tubercles being largest 

 near the ambitus both above and below the ambitus (PL XVIII. figs. 4, 5 ; PL XIX. 

 figs. 4, 5). In the ambulacral areas there are only secondary tubercles, three or four of 

 which on the abactinal side are somewhat larger than the others near the ambitus. From 

 the large primary interambulacral tubercles extends a more or less regular horizontal row 



' The new species of Asthaiosoma and of Phormosoma were inadvertently published with feminine terminations. 

 This error was not noticed in time to correct the lettering of the plates. 



