REPORT ON THE FORAMINIFERA. 
223 
The Oryzaria boscii of Defrance, as rendered by d’Orbigny in Model No. 50, is a 
better representative of the common recent forms of Alveolina than either the ovoid 
Miliolites sabulosus of Montfort or the somewhat attenuated Aveolina quoii of the 
“ Tableau Methodique ” ; but between the stout form with rounded extremities and the 
elongate subcylindrical varieties, every gradation of contour is to be met with. Under 
favourable conditions recent specimens of this species attain a length of half an inch (12 
or 13 mm.), and shells but little smaller than this are not uncommon. As previously 
stated, the internal structure of recent specimens is of the complex type, whilst fossil 
shells with the same external characters have for the most part undivided chamberlets. 
The geographical distribution of Alveolina boscii is confined to seas of warm latitudes, 
and scarcely exceeds the limits of the tropical zone ; but at certain depths within that 
area, wdiether in the Eastern or Western Hemisphere, it is one of the most plentiful and 
most generally diffused of the larger Foraminifera. It most affects the shallow water of 
coral-reefs, and becomes rare at greater depths than thirty fathoms. It nevertheless 
occurs in two deeper Challenger dredgings, namely, at Stations 260A, Honolulu Reefs, 
and 185, off Raine Island, depth 40 fathoms and 155 fathoms respectively, but in both 
cases the specimens are of very small size. 
In the fossil state Alveolina boscii is found from time to time throughout the 
Tertiary epoch, its earliest appearance being in the Eocene of the Paris Basin and in the 
Bracklesham Beds of Sussex and Hampshire. 
Alveolina melo, Fichtel and Moll, sp. (PI. XVII. figs. 13-15). 
Nautilus melo, Fichtel and Moll, 1803, Testae. Micr., p. 118, pi. xxiv. 
Borelis melano'ides, Montfort, 1808, Conch. System., vol. i. p. 171, genre xliii®. 
Clausulus indicator, Id. Ibid. p. 178, genre xlv®. 
Melonites splicer ica, Lamarck, 1816, Encycl. M6th., pi. cccclxix. fig. 1, a.-f. 
„ spheeroidea, Id. Ibid. pi. cccclxix. fig. 1, cj, h. 
Alveolina melo, d’Orbigny, 1826, Ann. Sci. Nat., vol. vii. p. 306, No. 2. 
Melonia costulata, Eichwald, 1830, Zool. Spec., vol. ii., pi. ii. fig. 1. 
Alveolina pulchra, d’Orbigny, 1839, Foram. Cuba, p. 85, pi. viii. figs. 19-22. 
„ hauerii, d’Orbigny, 1846, For. Foss. Vien., p. 148, pi. vii. figs. 17, 18. 
„ costulata, Ercbwald, 1853, Letb. Eossica, Deni. Periode, p. 8, pi i. fig. 4. 
Borelis melo, Ebrenberg, 1854, Mikrogeologie, pi. xxxvii. (sect. x. 10), fig. 1, a.-f. 
Alveolina melo, Parker and Jones, 1861, Ann. and Mag. Nat. Hist., ser 3, vol. viii. p. 164. 
„ „ Moebius, 1880, Foram. Mauritius, p. 79, pi. iv. figs. 2, 3. 
The spheroidal or broadly elliptical forms of Alveolina, typified by Alveolina melo, are 
much less common in the recent state than the elongate varieties. As already described, 
their internal structure is simpler than that of their living congeners, and in this respect 
they more nearly resemble some of the fossil species, especially those abounding in the 
limestones of the Nummulitic period or somewhat later. 
