127 
Among a number of Ophiactis profundi from Cook Strait, 120 
fms (collected 13/VIII.1920 by Mr. Hazelwood), sent me by Mr. 
W. R. B. Oliver, I found one small specimen of an Ophiactis, 
which I do not hesitate in referring to Ophiactis hirta Lyman, in 
spite of its differing from that species in a few minor characters. 
This specimen is a small one, measuring only 2,5 mm in dia¬ 
meter of the disk. It has only 6 arms, while the type specimen 
has 7 arms. That this could be a valid specific difference hardly 
anybody, who is familiar with the characters of Ophiurans, would 
Fig. 12. Ophiactis hirta I.yman. — a. Part of oral side, b. of dorsal side ; c. two arm¬ 
joints from middle of arm, dorsal side. *o/i. 
venture to maintain (— quite differently if we have to do with forms 
normally having 5 arms; comp. sub. O. profundi). The only other 
noteworthy differences to be observed between this specimen and 
the type, as figured by Ly man, are in the shape of the dorsal 
plates, which are more elongate in the New Zealand specimen 
than in the type, and in the oral papillæ being sligtly broader in 
the former than in the type. — I do not think that these small 
differences would justify us in distinguishing the New Zealand form 
even as a variety of the typical O. hirta. —■ The figures given here 
will serve to make clear the small differences from the type, and 
also to facilitate distinguishing this species from the other 6-armed 
Ophiactis occurring in New Zealand seas. 
It should be emphasized that in the specimen in hånd all the 
arms are equally developed, which may indicate that this species 
does not propagate through autotomy. 
