Foraminifera 5 M 



SPECIES OF FORAMINIFERA OBTAINED BY THE CANADIAN ARCTIC EXPEDITION. 



Hyperammina subnodosa H/B. Brady. 

 (See Plate I, figures 1, 2.) 



Rhabdopleura species, G. M. Dawson, Ann. Mag. Nat. Hist., ser. 4, vol. 7, 1871, 



p. 86 fig. 7. 

 Hyperammina subnodosa H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 



1884, p. 259, pi. 23, figs. 11-14. Awerinzew, Mem. Acad. Imp. Sci. St. 



Petersburg, ser. 8, vol. 29, No. 3, 1911, p. 12. Cushman, Bull. 104, U. S. 



Nat. Mus., pt. 1, 1918, p. 76, pi. 29, figs. 7, 8. 



Specimens are abundant from station 43a, and occur at 436. The largest 

 specimen measures 22 mm. in length, which seems to be a record for the species. 

 The proloculum is well marked, usually slightly greater in diameter than the 

 remainder of the test. The constrictions are well marked and numerous. The 

 wall is composed of rather fine sand grains of nearly uniform size light reddish 

 brown in colour, the apertural end much constricted in perfect specimens, the 

 aperture itself a small, simple, irregularly rounded opening. The tubes usually 

 have specimens of Tholosina bulla attached to the exterior. 



The finding of this species in abundance is especially interesting, as it is one 

 of the species not found by Kiaer in the material collected by the Fram in the 

 second Norwegian Expedition, in the region to the north of that in which the 

 Canadian Arctic Expedition material was collected. Awerinzew in his work 

 has considered H. subnodosa as one of the most characteristic species of the 

 Arctic. Along the Arctic coast of Siberia it is one of the commonest species. 

 Schlumberger recorded it from the cold water of the Okhotsk sea, and I have 

 had it from the same locality. Brady in the Challenger report mentions that 

 some of the finest specimens he had were from the coast of Greenland. In the 

 Atlantic I have found the species very abundant in very cold water, with bottom 

 temperatures below the freezing point, north of the Grand Banks of Newfound- 

 land. Pearcey records it from the Antarctic, and it is known from deep cold 

 waters in various parts of the ocean basins. 



Tholosina bulla (H. B. Brady.) 



(Plate I, figures 1, 2.) 



Placopsilina bulla H. B. Brady, Quart. Journ. Micros. Sci., vol. 21, 1881, p. 51: 

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 315, pi. 35, figs. 16, 17. 



Tholosina bulla Rhumbler, Nachr. Konigl. Ges. Wiss. Gottingen, 1895, p. 82. 

 Kiaer, Norske Nordhavs Expedition, No. 25, 1899, p. 4. Cushman, 

 Bull. 104, U.S. Nat. Mus., pt. 1, 1918, p. 63, pi. 25, fig. 6. 



Specimens are numerous at stations 43a and 436 attached to the outside 

 of the tubes of Hyperammina subnodosa, sometimes six or more being attached 

 to a single tube. The walls of T. bulla are made up of much finer material than 

 the tubes to which they are attached, showing a definite selective power of the 

 organism, usually of whitish grains, in decided contrast to the darker red colour 

 of the Hyperammina tubes. Near the edge are numerous acerose sponge spi- 

 cules. On the outside, especially near the top, are larger fragments of pebbles 

 or other foraminifera tests. These occur especially on the outside of the largest 

 specimens. In general, the longest diameter is in the direction of the long axis 

 of the tube to which it is attached. The wall is fairly thick, and of nearly 

 uniform texture, except for the points noted. A thin film of light-coloured 

 material covers the attachment, as a floor to the chamber. 



