FORAMINIFERA OF XORTH PACIFIC OCEAN, 



25 



Distribution. — The distribution of this species is very interesting. 

 According to the Challenger report, it was found once in the South 

 Atlantic and at a number of stations in the South Pacific, in from 

 410 to 1,350 fathoms. Flint records it from near Colon, Canal Zone, 

 in 896 fathoms. Bagg records it from two stations near the Hawaiian 

 Islands, station T 14430, in 1,544 fathoms, and station H4568, in 1,274 

 fathoms. In the material I have examined it has occurred very 

 frequently in the western North Pacific. Off the coast of Japan it 

 was often noted in the Albatross material, and also in the Nero 

 material from the line of soundings between Yokohama and Guam. 

 The depths range from 101 to S91 fathoms, with a single record 

 from 1,599 fathoms. 



Figs. 42-44.— Textularia quadrilatera. 42, megalorpheric form; a, front view; 6, side view; 

 c, apertural view. X 0(). 4:5, optical section through the early chambers of a megalo- 

 spheric specimen. X 60. 44, optical section through the early chambers of a microspheric 

 specimen. X 275. 



Both microspheric and megalospheric forms occurred in the 

 material examined. In the microspheric form, which is not com- 

 mon, the proloculum is very small and the initial end of the test very 

 tapering, the full width of the test not being attained until near its 

 completion. The microspheric proloculum in the specimens exam- 

 ined varied from 0.012 to 0.023 mm. in diameter. In the megalo- 

 spheric form the proloculum is much larger, often of nearly as great 

 a diameter as that of the completed test and greater than the thick- 

 ness of any other portion of the test. This form is therefore usually 

 less tapering, with nearly parallel sides. The megalospheric proloc- 

 ulum varied from 0.076 to 0.115 mm. In the record kept the ratio 

 of frequency of the megalospheric to the microspheric form was 

 about 6 to 1. 



