492 
THE VOYAGE OF H.M.S. CHALLENGER. 
C. Elongate cylindrical variety. 
Nodosaria ( Gl .) cequalis, Reuss. PL LXI. fig. 32. 
Glandulina incequalis, Egger, 1857, Neues Jahrb. fur Min. &c,, p. 305, pi. xv. figs. 26, 27. 
„ candela, Id. Ibid. p. 304, pi. xv. figs. 28, 29. 
„ cequalis, Reuss, 1863, Sitzungsb. d. k. Ak. Wiss. Wien, vol. xlviii. p. 48, pi. iii. fig. 28. 
„ Icevigata, var. cequalis, Reuss, 1870, Ibid. vol. lxii. p. 478 ; — 
Schlicht, 1870, Foram. Pietzpuhl, pi. vi. figs. 21, 22, 24. 
„ „ var. subcylindrica, Reuss, 1870, Ibid. p. 477 ; — Scblicht, Ibid. pi. vi. fig. 5. 
The typical Nodosaria ( Glandulina ) Icevigata of d’Orbigny has a subovate test, 
circular in transverse section, broadest a little above the middle, tapering rapidly towards 
the oral end which is somewhat rounded, and more gradually towards the opposite 
extremity which is acutely pointed. The segments are six in number, and embracing, the 
latest occupying more than half the visible shell ; and the sutures are marked externally by 
fine lines without the least superficial depression. This description applies to the author’s 
own figure (Ann. Sci. Nat., vol. vii. pi. x. figs. 1-3) ; but the drawing in Soldani’s “Testaceo- 
graphia,” which is referred by d’Orbigny to the same species ( loc . cit., p. 252), represents 
a three-chambered shell, broad and round in its oral aspect, obtuse and rounded at the initial 
end, with inflated segments and sunken sutures. These two drawings, taken in connection 
with Parker and Jones’s figures (Phil. Trans., vol. civ. pi. xiii. figs. 1-7), illustrate to some 
extent the variability of the species and its relation to the other straight Nodosarians. 
That d’Orbigny’s original figure indicates the typical characters of a particular group 
of short Nodosaria is evident from the fact that at localities in which such forms are 
rare the specimens are generally of the tapering sort with flush sutures ; but more than 
this can scarcely be affirmed. On the other hand, in districts over which Glandulina 
abound, as for instance in the warm area of the Faroe Channel at a depth of 530 fathoms, 
or thereabouts, the specimens present a very wide range of external contour — subglobular, 
elliptical, tapering and pointed, or subcylindrical — without much apparent preference for 
one shape above another, and in such infinite gradations that it is impossible to reduce them 
to anything resembling true specific or varietal groups. This view had become familiar 
to me before I was aware that the Rev. A. M. Norman had arrived at the same conclusion 
from the study of the specimens obtained from his Norwegian dredgings. The extreme 
variability is not confined to the general contour of the test, but it affects to a greater or 
less degree all the minor characters of the type. It is equally difficult to draw any 
distinction between varieties with flush sutures, and those in which the segments are more 
or less inflated and the septal lines correspondingly depressed ; indeed it would be quite- 
possible to arrange a series of recent specimens exhibiting every stage of modification, from 
the tapering subfusiform shell with even sutures, represented by the d’Orbignian drawing, 
to the fully-developed Nodosaria radicula with nearly globular segments. In the absence 
of any valid distinctive character the term Glandidina becomes a mere name of con- 
