112 " ENDEAVOUR " SCIENTIFIC RESULTS. 



I have been much puzzled by this Sea-urchin. It does 

 not look Hke any of the many specimens of P. magellanicus 

 which I have examined, but I am sure it is very nearly related 

 to that species. Indeed it is difficult to point out any im- 

 portant distinguishing features. Perhaps the two most 

 tangible differences are the narrow poriferous areas, with 

 vertical arcs of pores, in P. notius and the noticeable scarcity 

 of mihary tubercles ; in P. magellanicus miliary tubercles 

 are abundant and the poriferous areas are moderately wide 

 with the arcs of pores more or less oblique. The anal system 

 of P. notius looks quite different from that of P. magellanicus, 

 as it is nearly circular and is covered by much more numerous 

 plates. The presence of only one lateral tooth on the globi- 

 ferous pedicellarise, instead of one on each side as in P. 

 magellanicus, and the white primary spines of P. notius are also 

 worthy of mention, though perhaps not reliable specific 

 characters. It may also be mentioned, though I do not 

 lay any weight on the fact, that in P. magellanicus the buccal 

 plates bear numerous tridentate pedicellarise, while in P. 

 notius these plates are covered with ophicephalous. The 

 fact that all oculars are exsert in P. notius is interesting and 

 may ultimately prove to be a good specific character. The 

 general appearance of abactinal system, spines, pedicellarise 

 and buccal membrane is very much that of an Amhlypneustes, 

 but the test is very different, as are the buccal plates. It is 

 a pity the " Endeavour " did not secure an abundance of 

 specimens of Parechinus, for the Australasian species of the 

 genus sorely need elucidation and this single specimen only 

 adds to the difficulties ! 



Loc. — South of Gabo Island to south-east of Cape Everard, 

 Victoria, 70-80 fathoms. 



Genus Gymnechinus, Mortensen. 

 Gymnechinus epistichus, H. L. Clark. 



Gymnechinus epistichus, H. L. Clark, Mem. Mus. Comp. 

 Zool. Harvard, xxxiv., 1912, p. 289. 



This specimen resembles the holotype closely, but differs 

 in two points ; genital 3 (as not infrequently happens in this 

 genus) is completely shut out from the periproct, and the 

 primary spines, especially the actinal ones, are a decidedly 

 more distinct red. The horizontal diameter of the test is 

 22 mm. 



Loc. — Twenty-five miles south-east of Double Island Point, 

 Queensland. 



