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THE VOYAGE OF H.M.S. CHALLENGER. 
delicately thin and opalescent, the sutures appearing as conspicuous white lines. Aperture 
cribrate. Diameter, -^th inch (0'8 mm.). 
This is a very well-marked intermediate form, which may be classed either amongst 
Haucrinas or Spiroloculince with almost equal propriety. The cribrate aperture is a 
common character of Hauerina, but it is also an occasional feature of Miliolina. 
On the other hand, though the length of the segments is sometimes irregular, there are 
never more than two in each convolution, so that their general arrangement is that of 
Spiroloculina. In short, it may be regarded either as a Spiroloculina with porous 
aperture, or as a Hauerina with abnormally long segments ; and whichever view be 
adopted, it supplies an interesting connecting link between the two genera. 
Spiroloculina fragilissima is a rare coral-reef species. It occurs in two soundings off 
Tahiti, Society Islands, at 420 fathoms and 620 fathoms respectively ; off Kandavu, 
Fiji Islands, 255 fathoms ; at two Stations on the south coast of Papua, 3 to 28 fathoms, 
and at two points on the north coast of the same island, 16 to 25 fathoms. 
Spiroloculina robusta, n. sp. (PI. IX. figs. 7, 8). 
Test oblong or oval, with angular or pointed extremities, compressed or complanate ; 
broad and thick, slightly concave on both faces, rounded at the periphery. Segments few 
in number, much arched ; the inner margin of each overlapping a considerable portion of 
the previous segment on the same side, their lateral surfaces crested by angular ridges. 
Length, j^th inch (2’5 mm.). 
A very large fine species, found in the rich dredging off Culebra Island, West Indies, 
390 fathoms. 
Spiroloculina limbata, d’Orbigny (PI. IX. figs. 15-17 ; — Var. PI. X. figs. 1, 2). 
“Frumentaria Sigma et Rhombos,” Soldani, 1798, Testaceographia, vol. ii. p. 54, pi. xix. fig. m. 
Spiroloculina limbata, d’Orbigny, 1826, Ann. Sci. Nat., vol. vii. p. 299, No. 12. 
„ „ Bornemann, 1855, Zeitschr. d. deutsch. geol. Gesell., vol. vii. p. 348, pi. xix. 
fig. 1 , a, b. 
„ depressa, Williamson, 1858, Eec. For. Gt. Brit., p. 82, pi. vii. fig. 177. 
Miliola ( Spiroloculina ) limbata , Parker and Jones, 1865, Phil. Trans., vol. civ. p. 409, pi. xvii. 
fig. 83, a, b. 
Spiroloculina depressa, Terquem, 1875, Anim. sur la Plage de Dunkerque, p. 38, pi. v. fig. 18. 
The Soldanian figure on which d’Orbigny founded this species is far from satisfactory, 
but the name has been generally accepted for those Spiroloculine forms which have 
limbate sutural lines and square periphery. Bornemann’s figure, loc. cit., represents an 
excellent typical specimen from the Septaria-clay of Hermsdorf, just such an one as might 
be found living on our own coast at the present day. Prof. Williamson, and following 
