24 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



genera, especially Biloculina, are conspicuous members of deep-water 

 faunas, and in colder regions the prevalence of Biloculina in the " cold 

 area" of the north Atlantic led Brady to designate the bottom as 

 "Biloculina clay." 



Subfamily 1. CORNUSPIRININAE. 



Test usually free, the early stages composed of a proloculum and 

 elongate, coiled second chamber, later chambers t}^pically piano- 

 spiral, of various lengths in typical chambers of the included genera. 



Genus CORNUSPIRA Schultze, 1854. 



Orbis Philippi (part), Enum. Moll. Siciliae, vol. 2, 1844, p. 147. 



Opcrculina Czjzek (part), in Haidinger's Nat. Abhandl., vol. 2, 1848, p. 146. 



Cornuspira Schultze (type, C. foliacca Philippi), Organismus Polythal., 1854, 



p. 40.— H. B. Brady, Pvep. Voy. Challenger, Zoology, vol. 9, 1884, p. 198. 

 Spirillina Williamson (part), Rec. Foram. Great Britain, 1858, p. 91. 



Description. — Test consisting of a proloculum followed by a long 

 coiled tubular chamber, typically without septae, complanate, the 

 open end serving as the aperture, occasionally somewhat constricted 

 or with a thickened lip; wall porcellanous. 



This genus is the simplest of those of the whole family of the Mili- 

 olidae and is typical of the early development throughout the family 

 at least in the microspheric form hi highly accelerated species. It 

 is very similar to the primitive genera, Ammodiscus in the Lituolidae 

 and Spirillina in the Rotalidae. 



Some authors have treated the three genera, Ammodiscus, Cornu- 

 spira, and Spirillina as really the same thing with a selective char- 

 acter determining the kind of wall. It seems much better, however, 

 to take them as instances of parallelism in various families, much as 

 are found elsewhere in other groups. 



As a primitive genus Cornuspira should theoretically be found 

 early in the paleontological development of the family, and such is 

 the case, specimens referable to the genus having been recorded 

 from the Lias. However, as the type of wall may be obscured, the 

 mesozoic specimens are more or less dubious in character between 

 Spirillina and Cornuspira. Throughout the Tertiary it is found very 

 positively. 



CORNUSPIRA FOLIACEA, (Philippi). 



Plate 1, fig. 1; plate 2, fig. 1. 



Orbis foliaceus Philippi, Enum. Moll. Siciliae, vol. 2, 1844, p. 147, pi. 24, fig. 26. 



Cornuspira planorbis Schultze, Organismus Polythal., 1854, p. 40, pi. 2, fig. 21. 



Spirillina foliacea Williamson, Rec. Foram. Great Britain, 1858, p. 91, pi. 7, 

 figs. 199-201. 



Cornuspira foliacea Carpenter, Parker, and Jones, Introd. Foram., 1862, p. 

 68, pi. 5, fig. 16.— Reuss, Denkschr. Akad. Wiss. Wien, vol. 25, 1865, p. 

 121, pi. 1, figs. 8, 9. — Parker and Jones, Philos. Trans., vol. 155, 1865, 

 p. 408, pi. 15, fig. 33. — Butschli, in Bronn, Klassen imd Ordnungen, Thier- 

 Reichs, 1880, p. 189, pi. 4, fig. 8; pi. 8, fig. 1— Goes, Kongl. Svensk. Vet. 

 Akad. Handl., vol. 19, 1882, p. 120, pi. 9, figs. 308, 310— H. B. Brady, Rep. 



