FORAMINIFERA OF NORTH PACIFIC OCEAN. 



37 



the Hyalone ma-ground south of Japan. Bagg records it from the 

 vicinity of the Hawaiian Islands, but not all of his selected set are 

 of this species, and none of them are at all typical. 



From the 1906 cruise of the Albatross there is a large number of 

 specimens representing many stations ranging in depth from 59 to 500 

 fathoms, mostly off the southern coast of Japan, from the region from 

 which some of Brady's material was obtained, with one or two stations 

 in the Eastern Sea. From the Nero material the species is repre- 

 sented from stations south of Yokohama in 060 to 2,1 19 fathoms, the 

 latter being at the only station in this area from which the species 

 has been obtained from more than 

 1 ,500 fathoms. There are a few spec- 

 imens from Albatross station 113007, 

 near the Hawaiian Islands, in 323 

 fathoms, and from Tuscarora station 

 58, in SI 4 fathoms, south of the Bonin 

 Islands. 



In the material, microspheric and 

 megalospheric specimens have been 

 found at the same station, and the 

 measurement of the proloculum in 

 several cases has been obtained. 

 There seems to be no tendency toward 

 coiled young in the microspheric form, 

 so far as seen. 



There is a considerable variation 

 in the character of the lobulation of 

 the posterior border of the chambers and in the presence or absence 

 of the apical spine. Egger has described a species, B. acavlis, which 

 seems to include those forms which lack the spine and have the lobu- 

 lated margins of the chambers, but these characters are somewhat 

 variable. The microspheric form is the more tapering of the two. 



The figures show the extreme forms as made out in the material. 

 The spineless form with the deeper lobulations is that called B. 

 acavlis by Egger. 



BOLIVINA SEMIALATA Bagg. 



Bolivina semi-alata Bagg, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 139, pi. 5, fig. 3. 



Description. — Test broad, very much compressed, the early cham- 

 bers in a conical, little compressed test, the later chambers broad- 

 ening out, very much compressed, with a broad thin flange about 

 the periphery; apical end acuminate, with a short, rather stout, 

 spine; apertural margin very broadly rounded; posterior margin 

 of the flange with short, posteriorly directed tooth-like projections; 

 wall calcareous, thin, perforated with rather coarse perforations, 



] ]i. s. 59-60.— Bolivina robusta. 59. SPINE- 

 LESS VARIETY WITH DEEPLY LOBED CHAM- 

 BER MARGIN. X 100. 60, TYPICAL SPECI- 

 MEN WITH APICAL SPINE AND LESS DEEPLY 

 LOBED M \I;i.lX. X 70. 



