CHAP. IV.] 



THE CRUISES OF THE 



15!) 



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- 

 matida3. 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 debris has shown that this 

 second species, O. 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 

 form and are arranged nearly in 

 the same way; but parallel to 

 the outer row of large spines 

 on each interambulacral space 

 of four or five or more pedicellaria3, of quite a 

 peculiar type. The head of the pedicellaria which 

 is supported on a long stalk, consists of four valves 

 (Pig. 29), the wide terminal portion of each forming 



OJ. 29. Calreria fenestrata, 

 WYVILLE THOMSON. One of 

 the four-valved pedicellarise. 



there is a row 



