170 THE DEPTHS OF THE SEA. 
[CHAP, TV, 
Although many of the echinoderms of the cold 
area are common to the warm, the general facies 
of the echinoderm fauna is different, and there are 
a number of additional and very striking forms. 
Cidaris papillata, LESKE, is abundant at moderate 
Fig 31.—A llopora 
rculina, EHRENBERG. 
depths. On our second visit to the Holtenia ground 
we dredged one small specimen of the handsome 
urchin already described, Porocidaris purpurata. 
A fine brilhantly-coloured urchin of the Lchinus 
