117 
ance to this apparent difference. In some of the New Zealand spec- 
imens the genital slit appears to be no longer than in O. adiaphora, 
while in others it appears to reach to the edge of the disc. The 
bad preservation of the specimens in hånd makes it impossible to 
make out exactly how the genital slits really are in this species 
— in some places they even have the appearance of being divided 
into two parts, as in Ophioderma. 
I think it quite possible that both O. adiaphora and O. vilis will 
ultimately prove to be the same species as O. pentagona (also 
Clark points out the close resemblance of his species to O. pen¬ 
tagona). But for the present it seems to me more safe to regard 
the New Zealand form as a separate species, especially so long 
as O. pentagona or O. adiaphora have not been found in the Austral- 
ian seas. 
11 . Ophiothrix avistulata Lyman. 
Ophiothrix aristulata. Th. Lyman. 1882. Challenger Ophiuroidea, p. 
223, PI. XXI. Pigs. 9-12. 
— — R. Koehler. 1904. “Siboga“ Ophiuroidea. I. 
p. 151. 
— — H. Lym. Clark. 1915. Catalogue Recent Oph. 
p. 269. 
— — — 1916. Report on the Sea-Lilies, 
Starfishes, Brittle Stars and Sea-Urchins>. . . . 
“Endeavour“. Biol. Res. Fishing Experiments by 
the “Endeavour^. IV.p. 89. 
— sp. F J e f fr. B e 11. 1917. Echinoderma. British Antarctic 
(“Terra Nova“) Expedition 1910. Zoology IV.i. p 6. 
— aristulata. R. Koehler. 1922. Ophiurans of the Philippine 
seas and adjacent waters Buli. U. S. Nat. Mus. 
100. Vol 5, p. 205. PI. 35. 1—3. PI. 97.i. a-f. 
— — H. L. Clark. The Echinoderm Fauna of S. Africa. 
Ann. S. Afr. Museum. XIII. p. 336. 
The two specimens of Ophiothrix sp. from off Cape Maria van 
Diemen, mentioned by Bell (Op. cit.), which I have had the op- 
portunity of examining, undoubtedly belong to this characteristic 
species. They agree in all essential features with the description 
and figures given by Ly man. The keel on the dorsal midline of 
the arms is rather indistinct, more so in the larger specimen (dia¬ 
meter of disk 7 mm) than in the smaller one (6 mm). The only 
noteworthy difference from the type is that the spines on the 
