82 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



Description. — Test in front view broadly elliptical, in end view 

 compressed, chambers biconvex, the periphery with a definitively 

 developed thin carina, wall smooth except for occasional transverse 

 ribs usually indistinct; aperture slightly produced, broadly elliptical, 

 with a slightly thickened border joining the carina at its outer edge; 

 the aperture with a small bifid tooth. 



Length, up to 1 mm. 



Distribution. — Millett's material was from the Malay region. 

 The specimens here figured (type Cat. No. 9165, U.S.N. M.) are from 

 Hongkong Harbor. 



In his figures Millett apparently has two distinct species, one a 

 Quinqueloculina or Massalina with a conspicuous surface ornamenta- 

 tion of oblique costae near the peripheral border of the apertural end 

 of the chambers, the other a smooth Biloculina. All the figures are 

 of equal or greater magnification than figure 7, so that is apparently 

 not the young of the form shown in the other figures, 8 to 70. 



BILOCULINA SEMICOSTATA, new species. 

 Plate 34, fig. 6. 



Description. — Test in front view subcircular, in end view somewhat 

 compressed, biconvex; wall smooth except for the definite costae 

 of the ornamentation running from the aperture as a single median 

 longitudinal costa, soon becoming dichotomously divided into two, 

 which run slightly beyond the median point of the test, where they 

 gradually disappear; penultimate chamber with similar costae; 

 apertural end somewhat produced and contracted to form a sub- 

 cylindrical neck with a slightly thickened lip and broadly elliptical 

 aperture with a rounded tooth filling a large part of the aperture. 



Length, about 1 mm. 



Distribution. — Type-specimen (Cat. No. 9166, U.S.N.M.) from Nero 

 station 372 in 1,738 fathoms between Midway Island and Guam. 



The definite single median costae, becoming divided into two in 

 the central portion of the surface of the chamber, is the most striking 

 feature of this apparently deep-water species. 



BILOCULINA FLINTII, new species. 

 Plate 35, fig. 1. 



Description. — Test spinose, the periphery with a series of irregular 

 spinose projections and a stout spine in the middle of the surface 

 of each chamber; wall otherwise smooth, apertural end contracted 

 and extended into a short conical neck with a circular aperture and a 

 bifid tooth. 



Length, up to 1.35 mm. 



Distribution. — Type-specimen (Cat. No. 9167, U.S.N.M.) from a 

 Nero station near Midway Island, but without number. Other speci- 



