cuap.iv.]) THE CRUISES OF THE ‘PORCUPINE: 164 
weight by being lifted out of the water, and sink- 
ing slowly away back again to our inexpressible 
anguish ; glossy whisps of Myalonema spicules; a 
bushel of the pretty little mushroom-like 7isiphonia ; 
a fiery constellation of the scarlet Astropecten tenwis- 
pinus ; while a whole tangle was ensanguined by the 
‘disjecta membra’ of a splendid Brisinga. 
There was not much in the dredge-bag that was 
new. Some large Munide, with their ‘ sphéery eyne; ’ 
some fine specimens of Kophobeleninon milleri; an 
example of the Euryalid, Asteronyx lovén’, nearly 
the only Scandinavian echinoderm which we had not 
previously taken ; and an injured specimen of a 
flexible urchin, which we supposed to be of the same 
species as that procured the day before, although it 
differed greatly in colour, being of a uniform pale 
grey. Upon further examination, however, it proved 
to be the type of a totally different generic group of 
the same family. 
Phormosoma placenta resembles Calveria in having 
the perisom flexible, the plates overlapping in the 
same way and in the same directions; but the plates 
overlap one another only slightly, and they leave no 
membranous spaces between, so that they form a 
continuous shell. The great peculiarity of this form 
is that the upper surface is quite different from the 
lower. Above, the ambulacral and interambulacral 
areze are well defined and in ordinary proportion, 
the interambulacral areze being just twice as wide 
as the ambulacral, and the spines are much like 
those of Calveria, and are arranged nearly in the 
same manner. At the periphery the shell comes to 
a kind of ridge, and alters entirely; from the edge 
M 
