12 



TH. MORTENSEN. 



(Schwed. Siidpolar-Exp. 



Stereocidaris canaliculata. L. Doderlein. 1906. Echinoiden d. deutschen Tiefsee-Expedition p. 96, 102. 

 — R. Koehler. 1907. Asteries, Ophiures et Fxhinides recueillis dans les mers 



australes par la »Scotia> (1902— 1904). Zool. Anzeiger. XXXII. p. 143. 

 Austrocidaris — H. Lym. Clark. 1907. The Cidaridse. Bull. Mus. Comp. Zool. LI. p. 212. 



(?) Cidaris — F. Jeffr. Bell. 1908. Echinoderma. National Antarctic Expedition. Natural 



History. Vol. IV. Zoology, p. 5. 

 Stereocidaris — R. Koehler. 1908. Asteries, Ophiures et Fxhinides de l'Expedition antarctique 



nationale Lcossaise. Trans. R. Soc. Edinburgh. Vol. XLVI. p. 615. 

 Austrocidaris Th. Mortensen. 1909. Echinoiden d. deutschen Siidpolar-Expedition p. 37 — 39. 



Non: Cidaris nutrix WYV. THOMS. 



Goniocidaris membranipora STUDER. 

 Stereocidaris Lorioli Mrtsn. 



The rather intricate synonymic history of this species has probably at length come 

 to an end; after having been referred in the course of time to no less than 6 different 

 genera it has now been made the type of a new genus, Austrocidaris, and there it 

 will doubtless remain. To be sure the author of the genus, Professor H. LYM. Clark, 

 thinks it only slightly different from Dorocidaris — >were it not for their geo- 

 graphical isolation it would hardly be worth while to separate these three small 

 species from Dorocidaris*, he says (Op. cit. p. 212). This conclusion, however, can 

 only be arrived at, when the characters afforded by the pedicellariae are left out of 

 consideration. When these characters are taken into account — and I hope to have 

 proved in my »Echinoiden d. deutschen Sudpolar-Expedition», that the reasons pro- 

 duced by CLARK against using the pedicellarise in the classification of Cidaridse are 

 irrelevant — it is evident that Austrocidaris is not so very nearly related to Cidaris 

 {Dorocidaris), the pedicellark-e, on the contrary, decidedly point towards Stereocidaris 

 as the nearest relation. With Goniocidaris, to which genus most authors have re- 

 ferred it, following AGASSIZ, it is not very closely related, as DODERLEIN (Jap. See- 

 igeln p. 18) has sufficiently demonstrated. The deep median vertical furrow * — 

 the character which has caused its reference to this genus — is certainly very dif- 

 ferent (»durchaus nicht gleichwertig» DODERLEIN) from the depressions of the hori- 



* The alleged great variability of this furrow in canaliculata: it being sometimes very distinct, some- 

 times even totally absent, is due to the confusion of canaliculata with other species, especially Eurocidaris 

 nutrix. In true canaliculata it scarcely ever disappears. It is true, Doderlein states (Japanischen Seeigel p. 

 17) that in one of his specimens of canaliculata >findet sich keine Spur einer solchen Furche, das Miliarfeld 

 ist hier ganz flach und die Mittelnaht kaum zu erkennen>. He further states that all his specimens proceed 

 from Patagonia and the Magellan Strait, so that there should be no possibility of this specimen without 

 the deep median line being E. nutrix. On my applying to Professor Doderlein concerning this matter, 

 he most kindly sent me the specimen for examination, adding the information that it was bought from a 

 dealer in Naturalia in Basel, who had got it from Prof. Studer with other specimens of natural history 

 from the » Gazelle*. It was labelled >Gon. canaliculata, Ost-Patagonien». — The examination of this spe- 

 cimen shows beyond doubt — in spite of the absence of the characteristic large globiferous pedicellarire — 

 that it is Eurocidaris nutrix; especially the apical system, so different from that of A. canaliculata, leaves 

 no doubt of the identification. There must then evidently have been some confusion of the labels by the 

 dealer — or by Studer. Of course, this specimen could not be taken as a proof of the occurrence of E. 

 nutrix at Patagonia, against all other evidence. 



