EEPOET ON THE FOEAMINIFEEA. 
563 
Polymorphina sororia is less common than the type, but it has a similarly wide area 
of distribution. 
Polymorphina sororia , var. cuspidata, nov. (PL LX X T. figs. 17-19 ; PI. LXXII. 
fig. 4). 
A variety presenting the same general features as Polymorphina sororia, but more 
distinctly fusiform, and terminating at the initial end in a stout spine. 
This form has been met with at two points in the North Atlantic, west of Ireland, 
depth 808 fathoms and 1443 fathoms respectively; and at Station 146, about midway 
between the Cape of Good Hope and Kerguelen Island, 1375 fathoms. 
Polymorphina angusta, Egger (PI. LXXII. figs. 1-3). 
Polymorphina ( Globulina ) angusta, Egger, 1857, Neues Jalirb. fiir Min., &c., p. 290, pi. xiii. 
figs. 13-15. 
Polymorphina lanceolata, (pars) Eeuss, 1870, Sitzungsb. d. k. Ale. Wiss. Wien, vol. Ixii. p. 487, 
No. 12; — Schlicht, 1870, Foram. Pietzpuhl., pi. xxxi. figs. 2, 3, 4, &c. 
„ gracilis, Id. Ibid., p. 486, No. 7 ; — Schlicht, pi. xxxi. figs. 34-45, &c. 
„ fusiformis (pars), Brady, Parker, and Jones, 1870, Trans. Linn. Soc. Lond., 
vol. xxvii. p. 219. 
In the Monograph of the genus (Trans. Linn. Soc., vol. xxvii.), the small, starved, 
deep-water variety, of which the specimen figured by Egger ( loc . cit.), is a good example, 
was treated as one of the modifications of Polymorphina fusiformis ; but the sub- 
sequent study of a somewhat large series of recent specimens has led to the con- 
clusion that it possesses tolerably well-marked characters which it may be convenient 
to recognise by a distinctive name. 
In its typical condition, the test of Polymorphina angusta is of elongate-oval or 
subcylinclrical contour, with obtuse or rounded extremities, or sometimes pointed at the 
primordial end. It is usually composed of about four segments, which are long and 
erect ; the shell-wall is delicately thin and transparent, and the sutures are marked 
externally by fine lines. A more striking peculiarity is afforded by the fact that not 
unfrequently the septal walls are absorbed, so that the interior forms an undivided 
cavity. Specimens in this condition are often only distinguishable from varieties of 
Lagena Icevis by the remains of the external sutures ; and the generic resemblance is 
frequently enhanced by the presence of a short entosolenian tube. 
Polymorphina angusta is a widely diffused species. It occurs both in the North and 
South Atlantic, and in the North and South Pacific ; and though it most affects deep 
water, that is to say, bottoms ranging from 1000 to 2400 fathoms, it occurs also, from 
time to time, in shallower dredgings. 
As a fossil it has been found in the Miocene of Lower Bavaria (Egger), and in the 
Septaria-clays of Germany (Schlicht). 
