CHAP. 1V.] THE CRUISES OF THE ‘PORCUPINE, 159 
The spines are very delicate and hollow, with pro- 
jecting processes arranged in an imperfect spiral; and 
resemble somewhat the small spines of the Diade- 
matide. The colour of the test is a rich crimson with 
a dash of purple, and it is very permanent; the only 
perfect specimen procured which is 
preserved in spirit has not lost 
colour greatly to the present time. 
In the summer of 1870, Mr. 
Gwyn Jeffreys, dredging on the 
coast of Portugal, took two nearly 
perfect specimens and several frag- 
ments of another species of the 
genus Calveria; and subsequent 
careful examination of fragments 
and débris has shown that this 
second species, C. fenestrata, occurs 
likewise in the deep water off the 
coast of Scotland and Ireland. The 
interambulacral plates are nar- 
rower, and leave larger membra- 
nous spaces between them, and the 
great key-like overlapping expan- 
sions in the middle line are much 
larger. The spines have the same FP iN 
form and are arranged nearly in | Nige he aioe 
the same way; but parallel to  fyyueDiieliccnuie 
the outer row of large spines 
on each interambulacral space there is a row 
of four or five or more pedicellariw, of quite a 
peculiar type. The head of the pedicellaria, which 
is supported on a long stalk, consists of four valves 
(Fig. 29), the wide terminal portion of each forming 
