620 
THE YOYAGE OE H.M.S. CHALLENGER. 
Sphceroidina bulloides, d’Orbigny (PI. LXXXIV. figs. 1-7). 
Sphceroidina bulloides , d’Orbigny, 1826, Ann. Sci. Nat., vol. vii. p. 267, No. 1, — Module, 
No. 65. 
„ austriaca, Id. 1846, For. Foss. Tien., p. 284, pi. xx. figs. 19-21. 
Sexloculina haueri , Czjzek, 1847, Haidinger’s Naturw. Abhandl., vol. ii. p. 149, pi. xiii. 
figs. 35-38. 
Sphceroidina variabilis, Reuss, 1851, Zeitschr. d. deutscb. geol. GesellscL, vol. iii. p. 88, pL vii. 
figs. 61-64. . 
Grammobotrys parisiensis, Ehrenberg, 1854, Mikrogeologie, pi. xxvii. figs. 30, 31. 
Sphceroidina parisiensis, Id. Ibid. pi. xxvii. fig. 34. 
,, gemmula, Id. Ibid. ■ pi. xxx. fig. 22. 
bulloides, Parker, Jones, and Brady, 1865, Ann. and Mag. Nat. Hist., ser. 3, vol. xvi. 
p, .29, pi. in fig. 58. 
Bolbodium sphcerula, Ehrenberg, 1873, AbhandL d. k. Akad. Wiss. Berlin [1872], p. 388, pi. iv. 
fig- l 
In its typical presentment the test of Sphceroidina bulloides is nearly spherical, and 
is composed of a few extremely convex segments combined so as to form somewhat less 
than two convolutions of an involute spire. Each segment is considerably larger than 
its predecessor, and usually only those of the final convolution, three or four in number, 
are seen on the exterior; but -sometimes, owing to the asymmetry of the chambers or their 
more or less oblique setting, the earlier segments are visible on one side of the shell. 
The shell is quite smooth externally and is ■ stoutly built, having an average thickness of 
about 5 ^(jth inch. It often presents, a laminated structure, as shown in the section (fig. 
5), owing to the extension of the walls of the later chambers over those previously formed. 
The pseudopodial perforations are comparatively minute ; they are seldom visible 
externally and never conspicuous, but in section they appear as tubular canals, the 
larger of which scarcely exceed to (ph inch ( 0 ' 0 0 2 5 mm.) diameter. 
With reference to the nomenclature of the species,— the term Sphceroidina bulloides 
was originally applied by d’Orbigny, both to recent specimens obtained from the shores 
of the Adriatic and to similar shells from the later Tertiaries of Italy, and the distinctive 
characters were exemplified in one of the Models of his well-known series. Nevertheless, 
in the “ Vienna Basin ” monograph certain Miocene fossils, the figures and description 
of which correspond in every particular with the Model in question, are introduced under 
the name Sphceroidina austriaca, and this appellation has been commonly adopted, 
at any rate for fossil specimens, by subsequent writers. It is impossible to recog- 
nise the two forms as zoologically distinct ; indeed the entire list of “ species ” 
enumerated in the foregoing synonymy does not collectively embrace a much wider 
range of morphological characters than is represented by the group of figures on 
PI. LXXXIV. 
