Bd. VI: 4) 



THE ECHIKOIDEA. 



13 



zontal sutures so characteristic of Goiuocidni-is (though in large specimens of Gonio- 

 cidaris the vertical sutures are also deepened); also the pedicellarise are different — 

 especially the long end-tooth of the small globiferous pedicellariae in Goniocidaris is 

 a characteristic difference from Austrocidaris. — The nearest relation of Aiistrocida- 

 ris probably is the genus Eiirocidaris, established for the Kerguelen-species niiti'ix, 

 so long erroneously confounded with canaliculata. * The characters distinguishing 

 these two genera have been pointed out in my »Echinoiden d. deutschen Südpolar- 

 Expedition» (loc. cit.), to which I may refer. 



Though both Agassiz and DODERLEIN have given descriptions of this species, 

 the maintaining of E. mitvix as a distinct species — even of another genus — and 

 the establishing of the new species of Austrocidaris described below make a renewed 

 detailed description of canaliculata highly desirable. 



The test (Pi. IV Figs. 4—6, 8 — 11) is rather low, the height generally not ex- 

 ceeding half the horizontal diameter. The abactinal side is flat, or even — especiallj^ 

 in the females — considerably sunken. The actinal side is flat, the edge of the 

 peristome not incurved; the sides of the test beautifully rounded. 



The ambulacra (PI. XIV Fig. i) are about one fourth as wide as the inter- 

 ambulacra; the poriferous zone is a little narrower than the non-poriferous part of 

 the plates. The primary ambulacral tubercles are rather conspicuous; inside these 



* It is worth remarking that Wvv. Thomson, the author of nutrix, regards it as generically different 

 from canaliculata. referring the former to the genus CiJaris, the latter to Goniocidaris; this course is also 

 held by Studer in his »Übersicht d. Gazelle-Echinoiden». (Comp, also Meissner, Op. cit. p. 4.) 



