696 
THE VOYAGE OF H.M.S. CHALLENGEE. 
A deep-water variety, distinguished with difficulty from several allied and collateral 
forms. The test is small and neatly constructed ; the superior face exhibits fully three 
convolutions, the segmentation of which is marked externally by nearly straight, radial, 
non-limbate sutures. It is isomorphous with Truncatulina tenera. 
Pulvinulina umbonata is not a pelagic species. More or less characteristic specimens 
have been found in bottom- dredgings from five Stations in the North Atlantic, depth 
435 to 2750 fathoms; from five in the South Atlantic, 675 to 2475 fathoms; from 
twelve in the South Pacific, 37 to 2350 fathoms ; from three in the North Pacific, 345 to 
3125 fathoms ; and from one in the Southern Ocean, 1375 fathoms. 
It occurs in the Septaria-clays and other formations of early and middle Tertiary age 
in various parts of Central and Southern Europe (Reuss, Hantken, Seguenza, &c.). 
Pulvinulina exigua , n. sp. (PL CIII. figs. 13, 14). 
Test free, Rotaliform ; both faces convex, the inferior less so than the superior, 
periphery acute, lobulated ; composed of three convolutions, of which the outermost has 
usually five segments. Sutures non-limbate ; marked on the superior face by thickened 
lines of opaque-white shell-substance ; on the inferior by slight depressions. Diameter, 
^th inch (0‘4 mm.), or less. 
This is a deep-water variety, nearly related to Pulvinulina partschiana and Pulvinulina 
umbonata, from which forms it may be distinguished by its comparatively minute size, 
the smaller number of segments in each whorl, and their inflated contour, and the lobulated 
outline of the test. 
The record of its distribution is as follows: — twelve Stations in the North Atlantic, 
the depths ranging from 64 fathoms to 2740 fathoms ; four in the South Atlantic, 1025 
fathoms to 2475 fathoms; three in the Southern Ocean, 1300 fathoms to 2600 fathoms; 
ten in the South Pacific, 129 fathoms to 2350 fathoms; and five in the North Pacific, 
15 fathoms to 2300 fathoms. Of the thirty-four Stations enumerated, twenty-five 
have depths exceeding 1000 fathoms and fourteen exceeding 2000 fathoms. 
Pulvinulina pauper ata, Parker and Jones (PI. CIY. figs. 3-11). 
Pulvinulina repanda , var. menardii, subvar. pauperata, Parker and Jones, 1865, Phil. Trans., 
vol. civ. p. 395, pi. xvi. figs. 50, 51. 
This striking and interesting species is figured by Parker and Jones in their “ North 
Atlantic” memoir ( loc . cit .); but no descriptive characters are furnished, beyond the passing 
remark that “it presents a feeble, and, as it were, accidental condition, in which the thin 
film of sarcode surrounding the few feebly marked chambers has been calcified beyond 
their verge.” 
