224 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



565 fathoms (1,033 meters), between Panay and Negros, bottom tem- 

 perature 49.8° F. (9.8° C); D5185, in 638 fathoms (1,167 meters), 

 same region and same bottom temperature; D5222, in 195 fathoms 

 (356 meters), })etween Marinduque and Luzon, bottom temperature 

 52.8° F. (11.5° C); D5425, in 495 fathoms (904 meters), Jolo Sea, 

 bottom temperature 49.4° F. (9.7° C.) ; and D5470, east coast of Luzon^ 

 560 fathoms (1,024 meters). 



The variety is much less common than the typical form, but where 

 it occurs seems to be distinct. At only one station was it associated 

 with the typical form. 



Cristellaria rotulata, var. umbonata — Material examined. 



CRISTELLARIA ORBICULARIS (d'Orblgny). 



"Nuclei conico rotundati" Soldani, Testae eographia, vol. 2, 1798, App., p. 138, 



pi. 1, fig. 12. -p, P. 

 Robulina orbicularis d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 288, pi. 15, figs. 



8,9. 

 Cristellaria orbicularis H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 



p. 549, pi. 69, fig. 17.— CusHMAN, Bull. 71, U. S. Nat. Mus., pt. 3, 1913, p. 67, 



pi. 36, figa. 4, 5. 



This is one of the commonest species of Cristellaria in the region, 

 being found in a large number of stations in the Philippine Archi- 

 pelago proper; in the China Sea, off Formosa and off Hongkong; 

 southward at several stations oft' Sibuko Bay, Borneo; in Molucca 

 Passage; and between Gillolo and Kayoa Islands. 



The depths range from 43 to 565 fathoms (79 to 1,033 meters), 

 the average depth being 273 fathoms (499 meters). The average 

 bottom temperature for the stations when recorded is 50.7° F. (10.4° 

 C). 



The Challenger specimens were mostly from the South Pacific. 



Several distinct varieties occur in the region. 



