102 



BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



to the Hawaiian. Islands, in 392-2,615 fathoms, and in the Nero 

 material from about the Hawaiian Islands and Guam, and is 



common between Guam and Japan 

 at many stations. Among variously 

 scattered Tuscarora stations it oc- 

 curs in 500 fathoms just south of 

 the Aleutian Islands. It is a fairly 

 common constituent of globigerina- 

 ooze and volcanic muds in a num- 

 ber of areas of the 

 North Pacific, accord- 

 ing to the data avail- 

 able. 



There seems to be 

 some variation in the 

 shape and the amount 

 of spinosity developed. 

 In general the more 

 triangular forms are 

 most spinose and the 



Fig. 155.— E:irenb.ercuna serrata. X 75. a, ventral view; 6, dorsal view; c, ride view; 



d, apertural view. 



biconvex forms often almost smooth and frequently with the long 

 axis of the test considerably curved. 



EHRENBERGINA HYSTRIX H. B. Brady. 



Ehrenbergina hystrix H. B. Brady, Quart. Journ. Micr. Sci., vol. 21, 1881, p. 60; 

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 434, pi. 55, figs. 8-11.— Flint, 

 Bull. 55, U. S. Nat. Mus., 1905, pp. 16, 19. 



Description. — Test free, biserial, nearly as broad as long, stout; 

 dorsal border with spines often coalescing laterally to make a fringe- 

 like projection, later chambers smooth dorsally, the lateral margins 

 and ventral portion with large stout spines, the last developed cham- 

 ber often smooth and somewhat inflated, marked with fine raised 

 lines running radially outward from the aperture; wall fairly thick, 

 calcareous; aperture elongate, rounded at the inner end; color white. 



Length up to 1 mm. 



