125 
The differences between the Australian and the New Zealand 
forms pointed out by H. L. Clark (Op. cit. p. 301) are these: in 
O. resiliens the oral shields are much wider than long; adoral 
plates with no distally projecting angle separating oral shields from 
side arm-plates; in O. nomentis the oral shields are about as long as 
wide; adoral plates with a distally projecting angle separating oral 
Fig. 11. Ophiactis resiliens Lyman. — 1. Part of oral side; 2. of dorsal side; 3. arm¬ 
joints from middle of arm, oral side ; 4. same, dorsal side. 
shields from side arm-plates. Regarding the latter character, the 
distally projecting angle of the adoral shields, it is seen from the 
figure given here, drawn from a specimen from Slipper Island, that 
it may be wanting just as well in the New Zealand as in the 
Australian form; of two specimens of the Australian form sent me 
by H. L. Clark one has the distally projecting angle of the adoral 
shields very distinctly developed. This character thus is decidedly 
of no. value as a distinguishing feature. The difference in the shape 
of the oral shields thus remaining the only character to disting- 
uish the two forms is decidedly too insignificant and inconstant to 
