FOEAMINIFERA OP THE NORTH PACIFIC OCEAN. 35 



of the chamber; apertural end of the chamber produced to form an 

 elongated neck which has a well-developed phialine lip and a single 

 tooth on the inner margin of the aperture which is flattened on the 

 inner side; wall except for the costae smooth, white, dull. 



Diameter, up to 3.5 mm. 



Distribution. — Type-specimen (Cat. No. 9155, U.S.N.M.) from Nero 

 station 190 in 864 fathoms off Midway Island. The other material 

 was from Albatross station H2999 in 549 fathoms off the Hawaiian 

 Islands. 



This is a very large and striking species both in its general appear- 

 ance and in the feature of its partially uncoiling at the end of the 

 chamber in the adult test. This latter feature reminds one of the 

 similar character seen in some of the Quinqueloculinc group, but our 

 species is a true Spiroloculina as the transverse section here figured 

 shows. 



SPIROLOCULINA UNICOSTATA, new species. 

 Plate 7, figs. 1, 2. 



Description. — Test small, one side slightly convex, the opposite 

 side concave, chambers numerous; convex side of test marked by a 

 continuous costa or series of costae, one at the inner border of each 

 chamber, both ends of the last formed chamber produced, the basal 

 portion forming a bluntly rounded projection, the apertural end 

 with a produced cylindrical neck with broadly phialine lip, the aper- 

 ture circular and, as far as the specimens at hand show, there is no 

 tooth. 



Length, 0.30 mm. 



Distribution. — Type-specimen (Cat. No. 9156, U.S.N.M.) from Nero 

 station 1464 in 891 fathoms off Guam. 



This in some ways seems related to such concave speoies as S. ajjixa 

 Terquem and S. inaequilateralis Schlumberger. 



SPIROLOCULINA GRATA Terquem. 



Plate 7, figs. 3, 4. 



Spiroloculina grata Terquem, Mem. Soc. Geol. France, s6r. 3, vol. 1, 1878, p. 55, 

 pi. 5, figs. 14a-15&. — H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 

 1884, p. 155, pi. 10, figs. 16, 17. 



Description. — Test in front view rhomboid oval, the extremities 

 somewhat produced, giving an angular appearance to the test, in 

 end view with the sides parallel, the periphery well rounded; cham- 

 bers long and slender, cylindrical, circular in transverse section, the 

 surface marked by oblique longitudinal costae; apertural end of the 

 chamber produced to form a tapering neck, circular in transverse 

 section; the aperture circular with a single tooth on the inner margin; 

 surface of the test usually finely papillate as seen with higher magni- 

 fications; wall often brownish, translucent. 



Length, usually less than 1 mm. 



