210 
THE VOYAGE OF H.M.S. CHALLENGER. 
West Indies generally ; off the coast of South America (Station 122) ; in the Red Sea 
and Indian Ocean, amongst the East Indian Islands and the Philippines. Some 
uncertainty exists as to its occurrence in the Mediterranean, and further evidence on this 
point is still wanting. 
In the fossil condition its range extends as far hack as the Miocene epoch, and possibly 
to the Eocene, but there is no record of its appearance in prse-Tertiary times. 
Orbitolites, Lamarck. 
Helicites, pars, Guettard [1770]. 
Orbitolites , Lamarck [1801], Bronn, Goldfuss, Defrance, Blainville, Serres, Mickelin, d’Orbigny, 
Carpenter, Archiac and Haime, Parker and Jones, Carter, Norman, Brady, Moebius, 
Abich, &c. 
Discolithus, pars, Fortis [1802]. 
Discolites, Montfort [1808], 
Orbulites, pars, Lamarck [1816], Schweigger, Lamouroux, Deslongcliamps, Defrance, 
Blainville. 
Marginoporcc, Quoy and Gaimard [1833], Blainville. 
Orbitulites, Bronn [1838], Reuss, Karrer, Giimbel, Terquem, Hantken 
Sorites , AmpMsorus, Ehrenberg [1839]. 
Cupulites, pars, d’Orbigny [1847]. 
Orbiculina, pars, Williamson [1851], Jones, Parker, and Brady. 
Omphalocyclus, Bronn [1853]. 
Pavonina, Costa [1856]. 
The structural and morphological features of the genus Orbitolites have been 
repeatedly and exhaustively expounded by Dr. Carpenter, 1 whose latest researches, 
embodied . in his recent Challenger Report, leave nothing fresh to be said on the more 
important aspects of the subject. At the same time the genus is one of peculiar interest, 
as representing the highest and most complex development attained by the porcellanous 
group of Foraminifera, and it lies within the scope of the present Memoir to direct 
attention to the internal structure of the shelly skeleton of the various species, so far at 
any rate as may be requisite to understand the meaning of the external characters by 
1 Vide — 1850. On the Microscopic Structure of Nummulina, Orbitolites, and Orbitoides, Quart. Journ. Geol. Soc., vol- 
vi. p. 21, pis. iii-viii. 
1856. Researches on the Foraminifera, — Monograph of the Genus Orbitolites, Phil. Trans., p. 187, pis. iv.-ix. 
1862. Introduction to the Study of the Foraminifera, p. 105, pi. ix. 
1883. Report on the specimens of the Genus Orbitolites collected by H.M.S. Challenger during the years 
1873-1876, Zool. Chall. Exp., part xxi. pp. 1-49, pis. i.-viii. 
1883. Researches on the Foraminifera: Supplemental Memoir; on an Abyssal Type of the Genus Orbito- 
lites, a Study in the Theory of Descent, Phil. Trans. 
Nor should an early paper by Prof. W. C. Williamson be overlooked : — 
1851. On the Minute Structure of the Calcareous shells of some recent species of Foraminifera, Trans. Micr. 
Soc. Lond., vol. iii. p. 105, pis. xvii., xviii., 
in which the descriptions, though brief and provisional, were far in advance of any previously published. 
