218 Reviews — Wycille Thomson's " Depths of the Sea." 



getting the dredge capsized, we gave little heed to what seemed to 

 be an inevitable necessity — that it should be crushed to pieces. We 

 were soni\ewhat surprised, therefore, when it rolled out of the bag 

 uninjured ; and our surprise increased, and was certainly, in my 

 case, mingled with a certain amount of nervousness, when it 

 settled down quietly in the form of a round red cake, and began to 

 pant — a line of conduct, to say the least of it, very unusual in its 

 rigid, undemonstrative order. Yet there it was, with all the 

 ordinary characters of a sea-urchin, its inter-ambulacral areas, and 

 its ambulacral areas with their rows of tube feet, its spines, and five 

 sharp blue teeth ; and curious undulations were passing through its 

 perfectly flexible leather-like tests. I had to summon up some 

 resolution before taking the weird little monster in my hand, and 

 congratulating myself on the most interesting addition to my 

 favourite family which had been made for many a day. (See Figs. 

 2 and 3.) 



" I have named this genus Calveria hystrix, after our excellent 

 commander. Captain Calver, and his tidy little vessel, the ' Porcupine, ' 

 in grateful commemoration of the pleasant times we had together. 



"In the summer of 1870 Mr. Grwyn Jeffreys, dredging on the 

 coast of Portugal, took two nearly perfect specimens and several 

 fragments of another species of the genus Calveria; and subsequent 

 careful examination of fragments and debris has shown that this 

 second species, C. fenestrata, occurs likewise in the deep water off 

 the coast of Scotland and Ireland." (p. 159.) 



"Phormosoma placenta resembles Calveria in having a peristome 

 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 con- 

 tinuous shell. The great peculiarity of this form is that the upper 

 surface is quite different from the lower." (p. 161.) 



"We have thus become acquainted with three members of a 

 family of urchins which, while differing in a most marked way from 

 all other known living groups, bear a certain relation to some of 

 these, and easily fall into their place in urchin classification. They 

 are 'regular Echinids,' and have the normal number and arrange- 

 ment of the principal parts. They resemble the Cidaridce in the 

 continuation of the lines of ambulacral pores over the scaly mem- 

 brane of the peristome to the mouth, and they approach the 

 Diadematida in their hollow spines, in the form of their small 

 pedicellarise, and in the general structure of the jaw pyramid. From 

 both of these families they differ in the imbricated arrangement of 

 the plates, and in the structure of the pore-area, to the widest extent 

 compatible with belonging to the same sub-order. 



" Many years ago Mr. Wickham Flower, of Park Hill, Croydon, 

 procured a very curious fossil from the Upper Chalk of Higham, 

 near Eochester. It consisted of a number of series of imbricated 

 plates radiating from a centre, and while certain sets of these plates 

 were perforated with the characteristic double pores of the urchins, 

 these were absent in alternate series. Some points about this fossil, 



