OF THE KERGUELEN REGION OF THE GREAT SOUTHERN OCEAN. 383 



Ophiophyllum sp. (?). 

 <^phiot/iammis sp. {',). 

 *Ophiotholla supplicant, Lyman. 

 • *Ophiozona stellata, Tjyman. 



ECHINOIDKA : 



Aceste hellkU/eni,^ Wyville Thom?;ou. 

 Agpidodiadema - microhtberculatum, Agassiz. 

 Bfissopsis hizaniva (Gi"ay). 

 Ct/st(xhimi.i! eli/peatUii,'^ Agassiz. 

 * Echinus elegans (Dxxhcu aud Koreu). 



*Fhonnoso»ia asienas, Acjassiz. 

 * „ hoplacantha* Wyville Thomson. 



Pourtalesia lagtmcnla, Ag-assiz. 

 Salenia hastigera, Agassiz. 



disk, voitically ; which shows that the luuscukiv tension wust have some iieculiar proportion. . . . The peculiar 

 twisting upwai\l of the arms ami disk of U-phiomyces is explained by the abtseuce of radial shields, a want not yet 

 observed in any other genus. It seems, then, that one function of radial shields is to keep the disk in shape, somewhat 

 like the action of the sticks of an umbrella. — (LvM.\s, Zvvl. ChalL Kcp., part 14, pp. 240, 242.) 



' At fii-st glance Aa-stc bdlidifcm appears one of the most remarkable of y^ea-uivhins. . . . The enormous develop- 

 ment of the sucker of the odd anterior ambulacrum is an emiueutly embryonic feature ; it e.\ists in the youngest stages 

 of all the Spatangoids of which we know the development. . . . The general outline of the test as seen both in profile 

 aud from above is strikingly similar to that of the Schizasteridic. In fact, this genus is of the greatest iuteresi, showing 

 as it does striking attinities on the one side to the Scbizasteridse and other Spatangina, such as Brissifpsis, and on the 

 other to the P(>urtalesi;e, not only in the structure of its ambulacral system, but also from the position aud shape of 

 the actinostome, and the moi-e or less cylindrical test mollified in its outline from its Schinasterid attinities. — (Agassiz, 

 Zool. CludL E.cp., t>art t>, pp. lyu-ti.) 



" AspulodkuleiiM is a most intei-esting genus, intermediate between the Cid;uidie proper and the Diadematid». 

 It has like the latter a thin test, with long hollow primary spines nearly stiuight, and strongly verticillate, especially 

 in the young. . . . The most i-emarkable feature of this genus is the structure of the ambulacral system.— (Aoassiz, 

 Zool. C'haU. Kcp., pai-t i), pp. 64-5.) 



' The test of this species [('tistahiaus ditpeiUnJ] is (.(uite stout, judging fivm the thickness of the fragments 

 preserved. In the specimens from the gi-eatest depths at which this species has been found, the test is much thinner 

 than in the fragments which ai-e found near the 1000 fathom line. As a general rule among the Pourtalesi;e, the test 

 of the different species having an extended bathymelrical range varies very materially in thickness, according to the 

 depth at which the specimens were dj-e<lged, specimens of the same species from shallower j'egious having prettv 

 generally a comparatively stouter test. — (Ac;assi2!, Zool. Chall. Exp., jmrt 9, pp. 149-150.) 



' Phormosoma hopliuantha is the largest Sea-urchin with which 1 am acijuainted. It measures no less than 312 mm. 

 in diameter, and when fully cxpauiled, must have been a striking object. This species is remarkable for the large 

 size of the primary tubeiclcs arranged both on the actiual and abactinal surface of the iuterambulacral aj-eas iu 

 horizontal i-ows ; on the abactinal surface they are distant, separateil by large secondaries and n\iliaries, irregulailv 

 arranged on the coronal plates. ... In alcohol the colour of the specimens of this species is dark violet, almost 

 black lK)th for the test and spines, and this forme<.l a markeil contrast to the white tips of the spines on the actinal 

 surface. The e.\istence of primary spines tipped with hoofs as in the ArbaciadiC is an intei'esting structural feature, 

 connecting groups which thus far seemetl somewhat isolated in their relationship to other Echiuids. Thomson sjieaks 

 of the wear of the base of the cones as if they had l)een in use for " vigorous locomotion " over the grouml, as we know 

 to be the case iu one of the species of ArkwUi of the eastern North American coast. In the Kchiuothurid* the 

 conical tip does not extend along the sides of the exti-emity of the spine, forming, as iu the Arbaciadte, a kind of cap ; 

 it is merely attached by a nearly horizontal base to the moi^e flattened end of the spine. In consetiuence of this mode 

 of attachment the tip is frequently lost.— (Ai.;assiz, Zovl. ChalL &p., part 9, pp. Uil-2.) 



VOL. XX.Wm. I'AKT. U. (no. 10). 3 K 



