670 PROCEEDINGS OF THE NATIONAL MUSEUM. 



In continuation of the study of the Cambrian Brachiopoda ' the fol- 

 lowing notes have been assembled, which may be of service to students 

 prior to the publication of a monoofraph on the subject: 



Genus OBOLELLA Billings, 1861. 



1861. Ohohlla Billings, Pamphlet, and Geology of Vermont, II, p. 946, fig. 346. 



1861. Oholella Billings, Geol. Surv. Canada; Palfeozoic Fossils, I, p. 7,'fig! 7. 



1862. Oholdla Meek and Hayden, Proc. Acad. Nat. Sci. Phila., XIII,p. 4':3.5. 



1863. Oholella Hall, Sixteenth Rept. N. Y. State Cab. Nat. Hist., p. 133 'pi vi fia^ 



17-21. 'i • ' ^■• 



1865. OhoMla Meek and Haydex, Smithsonian Contl). Xo. 172, Palfeontology 



Upper Mi.'isouri, pp. 3, 4. 



1866. OhoMla Davidson, British Silurian Brachiopoda, |). 60. 



1867. Oholella Hall, Trans. Albany Inst., V, p. 108. 



1870. Oholella Dall, Am. Jour. Conchology, VI, pp. 162-164. 



1871. Oholella Billings, Canadian Naturalist and Geologist, new ser VI v. -^7 



figs. 5, 6. ' . 1 ■ - , 



1872. Oholella Billings, American Journal of Science, 3d ser.. Ill, p. 3.55, figs. 5 7. 

 1876. Oholella Billings, American Journal of Science, 3d ser., XI, p. l'76r 

 1881. Oholella Ford, American Journal of Science, 3d ser., XXI, p. 131. 



1884. Oholella? Walcott, Monograph U. S. Geol. Survey, VIII, Pahf^ontologv 

 Eureka District, pp. 67, 68. 



1886. Oholella Walcott, Bulletin U. S. Geol. Survey, No. 30, pp. 109-119. 



1889. Oholella Walcott, Proc. IT. S. National Museum, XII, p. 36. 



1892. Oholella Hall and Clarke, Pal. New York, YIII, Pt. 1, pp. 66, 164. 



1892. Oholella Matthew, Trans. Roy. Soc. Canada, IX, p. 39. 



1894. Oholella Hall and Clarke, Eleventh Annual Report New York State Geol- 

 ogist, p. 240, pi. Ill, figs. 5, 6, 7. 



1896. Oholella Mickwitz, Mem. Acad. Imp. Sci. St. Petersbourg, VIII, p. 116. 



Generic c/iaracters.—SheU subequivalve, moderatel}- convex; dorsal 

 valve more elevated at the umbo than the ventral; lonoitudinally ovate 

 or oval in outline, with the dorsal valve sometimes transversely oval. 

 Surface marked by concentric striw of growth and radiating* strite. 

 except in the subgenus 0. {Gh/2)tias) farom. which has irregula'i- trans- 

 verse lines crossing the concentric striae 



Shell substance unknown in an unaltered condition; it appears to 

 have been calcareo-corneous, as in Obolus. Shell structure formed of 

 a thin outer layer with many thin inner layers or lamella- more or le.s.s 

 oblique to the outer layer; the short lameflte of the anterior portion of 

 the valves are more oblique than the longer lamella of the central and 



iNote on the genus Lingulepis: Am. Jour. Sci., 4th ser.. Ill, 1897, pp. 404, 405. 



Cambrian Bi-achi.jpoda: genera Iphidea and Yorkia, with descriptions of new 

 species of each, and of the genus Acrothele: Proc. U. S. Nat. AIus XIX 1897 nn 

 707-718. ' ' -,. ^ . ..<, PI. 



Note on the brachiopod fauna of the quartzitic pebbles of the Carboniferous con- 

 glomerates of the Narragansett Basin, Rhode Island: Am. Jour. Sci. 4th ser VI 

 1898, pp. 327, 328. ' -^'■' ^ -i' 



Cambrian Brachiopoda: Obolus and Lingulella, with description of new snecies- 

 Proc. U.S. Nat. Mas. , XXI, 1898, pp. 385-420. 



