92 BULLETIN 10 4, UNITED STATES NATIONAL MUSEUM 



occurrence in these dredgings is very noteworthy. As will be seen from our 

 figure, the variety is very striking and distinctive, being strongly convex on the 

 one side and correspondingly concave on the other. The whole test is exceed- 

 ingly thin and delicate in structuie. The line of curvature is in the direction 

 of the short axis of the shell. Wiesner regards his specimens as a variety of S. 

 acutimargo Brady; from the curvature of the chambers it might equally be 

 regarded as allied to S. tenuis. The reason for the curvature of the chambers 

 is entirely obscure; it may possibly be due to the specimens growing adherent 

 to algae in the earlier stages of growth. 



Heron- Allen and Earland give a record of a single specimen from 

 oflF the west coast of Scotland, but Earland has very kindly sent me 

 a beautiful series of this variety from Porcupine Station 7, third 

 cruise, 48° 18' N.; 9° 11' W. in 93 fathoms. They have every indi- 

 cation of having been attached. 



It is quite probable that the Spiroloculina tenuiseptata of H. B. 

 Brady may belong in this genus, but a further study is necessary to 

 definitely place this species. It occurs widely distributed and excel- 

 lent specimens are from off the British Isles as well as from the 

 Mediterranean and Indo-Pacific. 



Genus DISCOSPIRINIA Munier-Chalmas. 1902 



Discospirinia Munier-Chalmas (Genotype, by designation, Orbitolites 

 tenuissima W. B. Carpenter), Bull. Soc. Geol. France, ser. 4, vol. 2, 

 1902, p. 352. — CusHMAN, Special Publ. No. 1, Cushman Lab. Foram' 

 Res., 1928, p. 165. 



Cyclophihalmidium Lister, in Lankester, A Treatise on Zoology, pt. 1, fasc. 

 II, 1903, p. 110 (footnote) (genoholotype, Orbitolites tenuissima W. B. 

 Carpenter). 



Orbitolites (part) of Authors. 



Test in the young similar to OpTithalmidium, later chambers annu- 

 lar with incomplete divisions into chamberlets; apertures at the 

 periphery of the very thin test. 



Tertiary and Recent. 



DISCOSPIRINIA TENUISSIMA (W. B. Carpenter) 



Orbitolites tenuissimus W. B. Carpenter, Proc. Roy. Soc, vol. 18, 1869, 

 p. 421; vol. 19, 1870, p. 155; in Wyville Thomson, Depths of the Sea, 

 1873, p. 91, text fig. 10.— Norman, Proc. Roy. Soc, vol. 25, 1876, 

 p. 211. — W. B. Carpenter, The Microscope, ed. 6, 1881, p. 556, text 

 fig. 318.^ScHLUMBERGER, Fcuille des Jeunes Nat., 1882, pi. 3, fig. 1. — 

 FoLiN, Congres Sci., Dax, 1882 (1883), p. 314, pi., fig. 5.— W.B. Carpenter, 

 Phil. Trans., vol. 174, 1883, p. 553, pis. 37, 38; Rep. Challenger "Orbitolites," 



1883, p. 16, pis. 1, 2.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 



1884, p. 212, pi. 15, figs. 6 a-d, 7. — J. Wright, Ann. Mag. Nat. Hist., ser. 

 6, vol. 4, 1889, p. 447.— Woodward, The Observer, vol. 4, 1893, p. 78.— 

 Flint, Ann. Rep't. U. S. Nat. Mus., 1897 (1899), p. 305, pi. 52. 



Orbitulites tenuissima Abich, Geol. Forsch. Kaukas. Landern, 1882, p. 243, 



fig. 41. 

 Discospirinia tenuissima Munier-Chalmas, Bull. Soc. Geol. France, ser. 



4, vol. 2, 1902, p. 352. — Cushman, Contr. Cushman Lab. Foram. Res., 



vol. 3, 1927, p. 37, pi. 8, fig. 6; Special Publ. No. 1, Cushman Lab. Foram. 



Res., 1928, p. 165, pi. 20, fig. 8; pi. 21, fig. 6. 



