REPORT ON THE FORAMINIEERA. 
195 
aspects. They represent transverse sections of Planispirina contraria, Planispirina 
exigua, and Planispirina sigmoidea respectively, accurately drawn by Mr. Hollick from 
specimens. Fig. b. is magnified to double the scale of the others, and shows that even 
the minute varieties have the same laminated shell as their larger congeners. In one 
of the lithographed figures of Planispirina communis (PI. CXIV. fig. 5), the abraded 
surface of the specimen demonstrates, even more strikingly than a transparent section, 
the thickening of the shell by successive layers. 
Planispirina contraria, d’Orbigny, sp. (PI. XI. figs. 10, 11 ; Woodcut, fig. 5, a.). 
“Nautilus” (pars), Soldani, 1780, Saggio Oritt., p. 100, pL ii. fig. 14, S. 
Biloculina contraria, d’Orbigny, 1846, For. Eoss. Vien., p. 266, pi. xvi. figs. 4-6. 
,, ,, Brady, 1864, Trans. Linn. Soc. Lond., vol. xxiv. p. 466, pi. xlviii. fig. 2. 
„ „ Reuss, 1867, Sitzungsb. d. k. Ak. Wiss. Wien, vol. lv. p. 70, pi. i. fig. 10. 
Nummoloculina contraria, Steinmann, 1881, Neues Jabrb. fur. Min., &c., N. S., vol. i. p. 34, pi. ii. 
Kauerina borealis, Brady, 1881, Quart. Journ. Micr. Sci., vol. xxi., N. S., p. 46. 
This species, the external features of which are well known from cl’Orbigny’s descrip- 
tion and drawings, may be accepted as the type of the genus. It has a stout discoidal 
planospiral shell, with thick rounded margin. The test is composed of six or seven 
convolutions, the number of segments increasing from two, in the early Milioline whorls, 
to five or six in the peripheral circuit ; the chambers are equitant, their umbilical margins 
spreading in Nummuline fashion over the two lateral faces of the test (Woodcut, fig. 5 , a.). 
The aperture is arched or dome-shaped, formed by the slightly constricted end of the 
terminal segment ; either open or partially closed by a shelly tongue projecting from the 
margin of the previous convolution. 
Between Planispirina contraria and the true Biloculince every degree of modifi- 
cation exists, Biloculina irregularis, d’Orbigny (PI. I. figs. 17, 18), being one of many 
intermediate varieties. 
Planispirina contraria is very widely distributed, but it does not seem to be 
abundant in the recent condition in any one locality. On our own shores it has been 
dredged off Shetland, in the Faroe Channel, among the Hebrides, and off the south-west 
of Ireland, at depths of from 40 to 100 fathoms. It occurs at three of the Challenger 
Stations in the North Atlantic at 1000, 1125, and 1675 fathoms respectively, and at 
three in the Pacific, namely, north of Papua 1075 fathoms, off Amboyna, 1425 fathoms, 
and off Valparaiso (?) 2160 fathoms. 
Its geological range does not appear to extend beyond the middle of the Tertiary 
epoch. It is found in the Miocene beds of the Vienna Basin (d’Orbigny), of Wieliczka 
(Reuss), and of Kostej (Karrer) ; and in the Pliocene of Coroncina (Soldani), and of 
Fossetta (Steinmann). 
