REPORT ON THE FOR AMIN IFERA . 
613 
Hastigerina pelagica, d’Orbigny, sp. (PI. LXXXIII. figs. 1-8). 
Nonionina pelagica, d’Orbigny, 1839, Foram. Amer. MAid., p. 27, pi. iii. figs. 13, 14. 
Lituola pelagica, Jones and Parker, 1860, Quart. Journ. Geol. Soc., vol. xvi. p. 302, table 
No. 181. 
Globigerrina pelagica, Parker and Jones, 1865, Phil. Trans., vol. civ. p. 366. 
Nonionina hyalina, Ehrenberg, 1873, Abhandl. d. k. Akad. Wiss. Berlin (1872), p. 388, pi. iv. 
fig. 4. 
Hastigerina murrayi, Wj. Thomson, 1876, Proc. Roy. Soc., vol. xxiv. p. 534, pis. xxii., xxiii. 
„ pelagica, Brady, 1879, Quart. Journ. Micr. Sci., vol. xix., N. S., p. 77. 
The test of Hastigerina pelagica is a nautiloid spire, either subglobular in contour or 
more or less compressed bilaterally, with excavated umbilici and lobulated periphery. 
Adult specimens attain a diameter of about -^jth inch (0'84 mm.). 
It is composed of somewhat less than two convolutions, of which the later, con- 
sisting of either five or six segments, completely encloses the earlier portions. The 
segments are much inflated, and each successively considerably larger than its predecessor. 
The aperture is a broad oval or arched opening, symmetrically placed at the inner margin 
of the final segment, sometimes bordered with a slightly thickened lip. The shell-wall 
is exceedingly delicate and transparent, and in living specimens is so thin that the out- 
line of the enclosed chambers and the form of the sarcode-lobes can be plainly traced 
by transmitted light. The pseudopodial perforations are very numerous and almost as 
minute as those of Sphceroidina bulloides, that is to say, about 8U o 0 th inch (0'003 mm.) 
in diameter, but they appear somewhat larger in worn bottom specimens. The surface 
of the test is beset with long, slender, needle-like spines, the sides of which are distinctly 
serrate, especially near the base. They are usually swollen at the point of union with 
the shell, and a slight constriction may generally be observed immediately above the 
thickened base. In some cases the spines appear to be hollow, but whether this is the 
rule, or indeed whether the appearance may not be due to the mode in which the 
specimens are mounted, I am unable to say with certainty. 
The species was repeatedly taken by means of the tow-net during the Challenger 
voyage, and the central figure of PI. LXXXIII. is copied from a drawing made by Mr. 
Wild from a living specimen. This is referred to by Mr. Murray in one of the Preliminary 
Keports 1 in the following terms: — “At times calcareous Foraminifera occur in vast 
numbers on the surface, and with a bottle can be picked up from a boat. In one specimen 
thus procured the sarcode of the animal was found thrown out into bubble-like exten- 
sions between the spines of the shell, and over these expansions of the sarcode and along 
the spines the pseudopodia moved freely and rapidly.” 
Hastigerina pelagica may be readily identified by the foregoing characters. The 
1 Proc. Roy. Soc., vol. xxiv. p 534. 
(ZOOL. CHALL. EXP. PART XXII.— 1884.) 
Y 78 
