Bd. VI: 4) 
THE ECHINOIDEA. 
13 
zontal sutures so characteristic of Goniocidaris (though in large specimens of Gonio- 
cidaris the vertical sutures are also deepened); also the pedicellariæ are different — 
especially the long end-tooth of the small globiferous pedicellariæ in Goniocidaris is 
a characteristic difference from Austrocidaris. -The nearest relation of Austrocida- 
ris probably is the genus Eurocidaris , established for the Kerguelen-species nutrix, 
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 DöDERLEIN have given descriptions of this species, 
the maintaining of E. nutrix 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. 
Dia- 
Height. 
Apical 
Anal 
Peri- 
Width of 
Plates of 
Longest 
Remarks. 
meter. 
system. 
system. 
stome. 
Ambu- 
Inter- 
Ambu- 
Inter- 
Radioles. 
lacra. 
ambul. 
lacra. 
ambul. 
mm. 
mm. 
mm. 
mm. 
mm. 
mm. 
mm. 
mm. 
9 
26 
V 
10.5 
7 
10.8 
3 
IZ . 5 
38-39 
8 
19 
d 
21 
10-5 
8.5 
5 -S 
9 
2.8 
9-5 
30-31 
OO 
1 
1 ^ 
— 
d 
20(19.5) 
10 
8.8 
5 
9 
2.6 
9-5 
29 
7 
— 
A little oblong. 
9 
17.8 
9 
7.8 
5 
8.8 
2 
8 
27—28 
7 
— 
d 
! 4 -S 
7 
6 
3.8 
7-5 
2 
6.8 
23—24 
6-7 
1 1 
9-5 
5 
4-5 
2.8 
5 
1-3 
4.8 
17—18 
6 
8.5 
8.2 
4 
4 
2.2 
4.2 
I 
4 
14-15 
6 
7-5 
No genital 
7 
3-5 
3-2 
2 
3-8 
I 
3-2 
12—13 
6 
6.8 
f 
openings. 
5 
21 
2-5 
2.8 
1-3 
2.8 
0.9 
2.1 
9—10 
5-6 
4 
14 
I 
00 kO 
— 
— 
— 
— 
— 
— 
— 
— 
12 
20 
1 1 
V 
1 4 - 5 
: 

— 
: 
— 

— 
— 
12.5 
HS 
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 — especially 
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. 1) 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 Wyv. Thomson, the author of nutrix , regards it as generically different 
from canaliculata , referring the former to the genus Cidaris , the latter to Goniocidaris ; this course is also 
held by Studer in his »Übersicht d. Gazelle-Echinoiden» . (Comp, also Meissner, Op. cit. p. 4.) 
