FORAMINIFERA OF THE NORTH PACIFIC OCEAN. 



15 



I have had specimens from material labelled "off Alaska" and 

 from Albatross station D4971 in 649 fathoms, bottom temperature 

 38.1° F. off Japan. 



DISCORBIS AURACANA (d'Orbigny). 



Plate 9, fig. 3. 



Rosalina auracana d'Orbigny, Voy. Amer. Merid., 1839, 



"Foraminiferes," p. 44, pi. 6, figs. 16-18. 

 Discorbina auracana Parker and Jones, Quart. Journ. Geol. 



Soc, vol. 28, 1872, p. 115.— H. B. Brady, Rep. Voy. 



Challenger, Zoology, vol. 9, 1884, p. 645, pi. 86, figs. 10, 



11. — Egger, Abh. kon. bay. Akad. Wiss. Miinchen, CI. n, 



vol. 18, 1893, p. 386, pi. 14, figs. 4-6.— Sidebottom, Mem. 



and Proc. Manchester Lit. and Philos. Soc, vol. 52, No. 



13, 1908, p. 12; vol. 54, No. 16, 1910, p. 25. 



Description. — Test small, plano-convex, dorsal side 

 slightly convex, ventral side flat or slightly concave, 

 peripheral margin rather acutely rounded; chambers 

 six to nine in the last-formed whorl, sutures slightly 

 depressed, often limbate with clear shell material, 

 early chambers often carinate with similar material; 

 wall finely punctate; aperture a narrow, curved slit at 

 the margin of the ventral side of the chamber; color 

 brownish, especially the earlier chambers. 



Diameter 0.30-0.50 mm. 



Distribution. — Apparently the only North Pacific record for this 

 species is that of Brady, who records it from the shores of Japan. I 

 have not found well-characterized specimens. 



DISCORBIS ISABELLEANA (d'Orbigny). 

 Plate 6, fig. 1. 



Rosalina isabelleana d'Orbigny, Voy. Amer. Merid., 1839, " Foraminiferes," p. 

 43, pi. 6, figs. 10-12. 



Discorbina isabelleana Parker and Jones, Quart. Journ. Geol. Soc, vol. 28, 1872, 



p. 115. — H. B. Brady, Rep. Voy. 

 Challenger, Zoology, vol. 9, 1884, 

 p. 646, pi. 88, figs. la-c. — Egger, 

 Abh. kon. bay. Akad. Wiss. Miin- 

 chen, CI. ii, vol. 18, 1893, p. 386, 

 pi. 15, figs. 36-38. 



Description. — Test biconvex, 

 smooth, five to six chambers in a 

 o ventral view; 6, side view; c, dorsal co j^ fiinbate dorsally, ventrally the 



view. (After d'Orbignt's type figure.) t , ..,.,. 



sutures depressed; umbilical region 

 filled and umbonate; peripheral margin acute; aperture a narrow 

 slit extending backward from the margin toward the umbilical region. 

 Diameter 0.25-0.40 mm. 



c 



Fig. 15.— Discorbis 



AURACANA (d'OR- 



bigny). (Adapted 

 from type figure 

 of d'Orbigny.) 

 a, dorsal view; 6, 

 side view; c, ven- 

 tral VIEW. 



Fig. 16. 



ad ' c 



-Discorbis isabelleana (d'Orbigny). 



