FOEAMINIFERA OF THE NORTH PACIFIC OCEAN. 



67 



As a rule T. tricarinata seems to be found in deeper water than 

 its closely allied species, T. trigonula. 



From one station, D5056 off Japan in 258 fathoms, very large speci- 

 mens occur with a cruciate aperture similar to the species named by 



Fig. 32.— Triloculina tricarinata d'Orbigny. X13. Outline figure showing the apertural 



CHARACTERS. 



d'Orbigny Cruciloculina triangularis. Sufficient material was not 

 available for a study of the young stages to compare them with sim- 

 ilar stages of smaller specimens of T. tricarinata. 



TRILOCUXINA CIRCULARIS Bornemann. 



Plate 25, fig. 4; plate 26, fig. 1. 



Tnloculina circularis Bornemann, Zeitschr. deutsch. geol. Ges., vol. 7, 1855, 



p. 349, pi. 19, fig. 4. 

 Miliolina circularis H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 



p. 169, pi. 4, fig. 3a-c; pi. 5, figs. 13, 14?— Goes, Bull. Mus. Comp. Zool., 



vol. 29, 1896, p. 82. 



Fig. 33.— Triloculina circularis (Bornemann). X36. Young specimen still in the quinqueloc- 



ULINE STAGE FROM HONGKONG HARBOR. 



Description. — Test rounded, the three visible chambers in the 

 adult rounded and tumid, sutures distinct, whole test somewhat 

 compressed, the last-formed chamber strongly embracing, wall 

 smooth; aperture a crescentiform narrow slit with a large flattened 

 semicircular tooth. 



Length, about 1 mm. 



Distribution. — The only definite published North Pacific record for 

 this species seems to be that given by Goes, Albatross 1)3407 in 885 



