90 BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



Ophthalmidium inconstans — material examined 



OPHTHALMIDIUM CARINATUM Balkwill and J. Wright 



Ophthalmidium carinatum Balkwill and J. Wright, Trans. Roy. Irish Acad., 

 vol. 28, Sci., 1885, p. 326, pi. 12, figs. 13-16.— J. Wright, Proc. Roy. 

 Irish Acad., ser. 3, vol. 1, 1891, p. 465. — Heron-Allen and Earland, 

 Proc. Roy. Irish Acad., vol. 31, pt. 64, 1913, p. 34; Trans. Linn. Soc. 

 London, ser. 2, vol. 11, 1916, p. 215. 



"Shell much compressed, subdiscoidal, equilateral, showing all the 

 convolutions; peripheral margin with a narrow keel, composed of a 

 few convolutions slightly embracing; segments few, swollen at the 

 base and getting narrower toward the superior end, each forming 

 about two-thirds of a convolution; aperture simple, terminal." 



This seems to be a fairly constant species in its restricted habitat 

 about the British Isles. I have not seen material and nothing like 

 it has occured in the collections from the western side of the Atlantic 

 which I have examined. 



Genus SPIROPTHALMIDIUM Cushman, 1927 



. Spiropthalmidium Cushman (Genoholotype, Spiroculina acutimargo H. B. 

 Brady (part)), Contr. Cushman Lab. Foram. Res., vol. 3, 1927, p. 37; 

 Special Publ. No. 1, Cushman Lab. Foram. Res., 1928, p. 165. 

 Spiroloculina (part) H. B. Brady (not d'Orbigny), Rep. Voy. Challenger^ 

 Zoology, vol. 9, 1884, p. 154. 



Test similar to Ophthalmidium, but accelerated, the stage having 

 two chambers in a coil quickly reached ; plate between the chambers 

 usually present; aperture simple, without teeth. 



Lias to Recent. 



This seems to be somewhat of a left-over from older periods as are 

 Ophthalmidium and Discospirinia. There are very few living forms. 

 There is a strong resemblance to Spiroloculina, but the developmental 

 stages are different and there is no apertural tooth. 



SPIROPTHALMIDIUM ACUTIMARGO H. B, Brady 



Plate 22, Figure 1 



Spiroloculina acutimargo H. B. Brady (part). Rep. Voy. Challenger, Zoology, 

 vol. 9, 1884, p. 154, pi. 10, fig. 13 (not figs. 12, 14, 15).— Balkwill and 

 J. Wright, Trans. Roy. Irish Acad., vol. 28, Sci., 1885, p. 323. — Siddall, 

 Proc. Lit. Phil. Soc. Liverpool, 1886, p. 72 (list). — Halkyard, Trans. 

 Manchester Micr. Soc, 1889, p. 59. — Chaster, First Rept. Southport 

 Soc. Nat. Sci., 1890-91 (1892), p. 55.— J. Wright, Proc. Roy. Irish Acad., 

 ser. 3, vol. 1, 1891, p. 463. — Millett, Journ. Roy. Micr. Soc, 1898, p. 



