4 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



This genus is known from as far back as the lower Cretaceous. 

 Some of the species have a very elongate biserial condition, and in 

 others the two parts are nearly equal. In some species of Textularia 

 also there is a coiled stage in the early development of the micro- 

 spheric form, but it is not usually present in the megalospheric form 

 of the same species. 



Spiroplecta is here limited to the species which show both in the 

 microspheric and megalospheric forms a definite coiled stage. The 

 best developed species seem to be from the Indo-Pacific region, but 

 Spiroplecta hiformis seems to be very largely a species of cold waters. 



SPIROPLECTA BIFORMIS (Parker and Jones). 



Textularia agglutinans d'Orbigny, var. hiformis Parker and Jones, Philos. 

 Trans., vol. 155, 1865, p. 370, pi. 15, figs. 23, 24. 



Textularia hiformis H. B. Brady, Ann. Mag. Nat. Hist., ser. 5, vol. 1, 1878, p. 

 436, pi. 20, fig. 8. 



Spiroplecta hiformis H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 

 p. 376, pi. 45, figs. 25-27. — ^Balkwill and Wright, Trans. Roy. Irish Acad., 

 vol. 28, 1885, p. 333, pi. 13, fig. 21.— H. B. Brady, Journ. Roy. Micr. Soc, 

 1887, p. 895. — ScHLUMBERGER, M^m. Soc. Zool. France, 1894, p. 239. — 

 Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 25, No. 9, 1894, p. 38, pi. 7, 

 figs. 308-312. — Whiteaves, Geol. Survey Canada, 1901, p. 10. — Earland, 

 Journ. Quekett Micr. Club., ser. 2, vol. 9, 1905, p. 204. — Awerinzew, Mem. 

 Acad. Imp. Sci. St. Petersburg, ser. 8, vol. 29, No. 3, 1911, p. 17.— Kiaer, 

 in Due d'Orleans Crois. Ocean, M^r du Gronland, 1905 (1907), p. 560. — 

 Heron-Allen and Earland, Journ. Roy. Micr. Soc, 1908, p. 310; Proc. 

 Roy. Irish Acad., vol. 31, pt. 64, 1913, p. 56.— Pearcey, Trans. Roy. Soc. 

 Edinburgh, vol. 49, 1914, p. 1012. — Heron-Allen and Earland, Trans. 

 Linn. Soc. London, vol. 11, ser. 2, 1916, p. 231. — Sidebottom, Journ. Roy. 

 Micr. Soc, 1918. p. 22. 



Description. — ^Test small, elongate, compressed, initial end broadly 

 rounded, sides nearly parallel, rounded, apertural end bluntly pointed; 

 early chambers close-coiled, later ones biserial, inflated; sutures dis- 

 tinct, depressed, wall arenaceous, with reddish-brown cement, rather 

 smoothly finished on the exterior; aperture at the base of the inner 

 margin of the last-formed chamber. 



Length about 0.25 mm. 



Distribution. — Parker and Jones described this species from off the 

 Hunde Islands, Davis Strait, in 60 to 70 fathoms (110 to 128 meters). 

 From the known records of this species it is characteristically an 

 Arctic species of comparatively shallow water and very deep cold 

 water elsewhere. Specimens are recorded from the coasts of Europe 

 and the British Isles and in the Gulf of St. Lawrence. In the Arctic 

 it is known from off Franz Josef Land, the west coast of Nova Zembla, 

 Baffin Bay and Smith Sound, Spitzbergen, Barents Sea, Nordenskiold 

 Sea, at depths ranging from 2 to 270 fathoms (4 to 496 meters), and 

 in the Antarctic in 2,110 fathoms (3,859 meters), Scotia station 337A 

 (Pearcey) . 



