and perhaps therefore grown a little larger. This is, of course, 
nothing but a suggestion. Observations on a larger material, and 
especially on living specimens, will be needed to settie the question 
how the difference described is to be explained. 
The discovery that O. brevirima is viviparous naturally led to 
the suggestion that it might then perhaps prove to be identical 
with the Ophiomyxa vivipara Studer of the Magellanic region. This 
it is, however, not. There is a conspicuous difference in the shape 
of the ventral plates (see fig. 6) as also in the dorsal plates; the 
two large lateral plates are not found in O. vivipara, the whole 
a. b. 
Fig. 6. Part of ventral side of Ophiomyxa vivipara ; 
a. of a specimen from the Cape region, b. of a specimen from Patagonia. ®/i. 
dorsal side of the arm being occupied by one large, thin and del- 
icate fenestrated plate. It should be pointed out that O. brevirima 
has separate sexes, as is also the case with O. vivipara. 
I would still add that probably the specimens from the Cape 
region referred to Ophiomyxa vivipara do not really belong to that 
species, but represent a separate species, as is also suggested by 
H. L. Clark in his “Echinoderm Fauna of South Africa“.^) I shall 
not, however, enter on a discussion of this question here. 
10 . Ophiacantha vilis n. sp. 
Figs. 7. a —d. 
Some specimens from Cooks Strait, 200 fathoms (collected by 
Mr. Hazelwood, 1920) were sent me by Mr. W. R. B. Oliver. 
They are all in a rather poor State of preservation. 
1) Annals of the S. African Museum. XIII. 1923; p. 313. 
