92 THE DEPTHS OF THE SEA. 



[CHAP. in. 



thin as paper. Prom its extreme tenuity and the 

 ease with which the rings of chamberlets of which 

 it is composed separate from one another, all our 

 large specimens were more or less injured. All 

 the chamherlets are on the same plane; this spe- 

 cies therefore belongs to the ' simple type ' of the 

 genus, though the form of the chamherlets corre- 

 sponds, as Dr. Carpenter has pointed out, with those 

 of the superficial layer in the complex type. Another 

 peculiarity which Dr. Carpenter regards as of special 

 importance in its general bearings, is that, instead of 

 commencing with a ' central ' and ' circumambient ' 

 chamber like the ordinary Orbitolites, this form com- 

 mences with a spine of several turns like that of a 

 young Cornuspira, thus showing the fundamental 

 conformity of this cyclical type to the spiral plan of 

 growth. 1 



As I have already mentioned, it was the original 

 intention to devote the second cruise to the exploration 

 of an area to the west of the outer Hebrides, between ! 

 Rockall and the south-western limit of last year's 

 work in the Lightning.' During the first cruise 

 however dredging had been carried down successfully 

 to a depth of nearly 1,500 fathoms ; and the result 

 so far realized our anticipations, and confirmed the 

 experience of last year. The conditions (to that 

 great depth at all events) were consistent with the life 



1 Researches on the Foraminifera. Part I. In the Philosophical 

 Transactions of the Royal Society of London for the year 1855. 

 P. 193 et seq. 



Introduction to the Study of the Foraminifera. By William B. 

 Carpenter, M.D., F.R.S., F.L.S., F.G.S., &c. Published for the Rayi 

 Society, 1862. P. 106 et seq. 



