168 



THREE CKUISES OF THE b BLAKE. 



shells, enabling them to float with greater facility by increasing 

 their surface immensely. When alive, " the sheaves of these 

 spines cross in different directions, and have a very beautiful 

 effect." The inner chambers are filled with a colored sarcode, 

 either red or orange. No trace of pseudopodia has as yet been 

 observed, or any extension of the sarcode beyond the shell. 



Globigerina bulloidea has been found pelagic everywhere in 

 the West Indies, as well as in the bottom dredgings of the Ca- 

 ribbean and the Gulf Stream. It is not so abundant after pass- 

 ing north of Cape Hatteras. I have not found it pelagic off the 

 coast of the Middle States. Hastigerina is eminently a pelagic 

 type. It had been known from the coast of South America 

 many years previously to its rediscovery by the " Challenger." 

 It is not an uncommon pelagic type off the Tortugas, and was 

 found on one occasion, on a very calm day, swarming on the 

 surface with Globigerina bulloides. 



A minute scale-like foraniiuifer, Discorbina orbicularis, is 

 commonly found in the coral reefs of the West Indies. An- 

 other peculiar form, also found living in the West Indian reefs, 



Fig. 513. Cymbalopora bulloides. 4 f 5 . (Challenger.) 



is Cymbalopora ; one of the species of the genus, however, C. 

 'bulloides (Fig. 513), is also pelagic. 



The most protean of West Indian rhizopods is perhaps Car- 

 pentaria balaniformis. (Fig. 514.) Its regular structure is 



Fig. 514. Carpentaria balanif ormis. 



(Goes.) 



rotaline, but, owing to its propensity for ' developing additional 

 chambers from the upper extremity and from the chamber 



