220 
THE VOYAGE OF H.M.S. CHALLENGER. 
observed off Ascension Island, 7 fathoms; off the coast of South America, near Pernambuco, 
350 fathoms ; off Cape de Yerde Islands, 11 fathoms; off Sombrero Island, 450 fathoms, 
and elsewhere in the West Indies ; and in coral-sands from Bermuda. 
Owing to the confusion in which the nomenclature is involved, it is difficult to state 
precisely the geological range of this species. Gtimbel has described and figured, under the 
name Orbitulites 'precursor, an Orbitolite of the complex type, obtained from the Alpine 
Lias of the neighbourhood of Roveredo, which appears to differ in no important particular 
from the living representatives of the present form, except in its small and somewhat 
obscure spiral commencement. Setting this aside, probably the earliest known appearance 
of the species is in the Upper Cretaceous formation of Maestricht and elsewhere in the Low 
Countries (Faujas, Hagenow, Bronn). It occurs in the Early Tertiaries of the Gironde 
(d’Orbigny) ; in the “ Calcaire grossier” of the vicinity of Paris (Lamarck, d’Orbigny, 
Goldfuss, &c.), and in that of Forets and St. Gilles in Belgium (Galeotti) ; in the 
“ Calcaire moellon ” of Montpellier (Serres) ; in the Bracklesham Beds of Hampshire, 
(Fisher) ; and in the yellow Nummulitic Limestone of North-Western India (Archiac). 
Lastly, it has been found in the Miocene of Malta (Brady), and in the Crag of the east of 
England (Jones, Parker, and Brady). 
Orbitolites complanata, var. laciniata, H. B. Brady (PI. XVI. figs. 8-11). 
“ Orbitolites with, plicate margin,” Carpenter, 1856, Phil. Trans., pi. v. figs. 2, 3. 
“ Orbitolites, complicirte Varietat,” Biitschli, 1880, Bronn’s Kl. u. Ord. d. Thier-Reichs, vol. i. 
pL v. fig. 4. 
Orbitolites laciniatus, Brady, 1881, Quart. Journ. Micr. Sci., vol. xxi. N. S., p. 47. 
Orbitolites complanata, var. laciniata, Carpenter, 1883, Report on the Genus Orbitolites, Zool. 
Chall. Exp., part xxi., pi. vii. 
This is an exceedingly interesting modification of Orbitolites complanata. The 
central portions of the test show but little deviation from the normal plan of growth ; 
but near the margin, the disk becomes strongly sinuate or crumpled, and usually at the 
same time splits horizontally so as to form a double periphery, the two edges of which 
approximate at intervals, but otherwise are separated by deep irregular fissures. Under 
favourable conditions the specimens attain very large dimensions, and are not unfrequently 
an inch (25 mm.) or more in diameter. The division of the margin entails no departure 
from the typical structure, as each lamella presents the same arrangement of the parts as 
the disk itself ; but in some of the outer annuli the partitioning into chamberlets is often 
incomplete or altogether wanting (PI. XVI. fig. 11). 
The salient peculiarities of the test are no doubt the result of exuberant growth, and 
consequently assume a great diversity of form ; but although no two specimens are 
exactly alike in the shape or extent of the marginal development, the same general 
