172 
THE VOYAGE OF H.M.S. CHALLENGER. 
Miliolina bicornis, Williamson, 1858, Rec. For. Gt. Br., p. 87, pi. vii. figs. 190-192. 
Quinqueloculina brongniartii, Jones, Parker, and Brady, 1866, Foram. Crag, p. 14, pL iii. figs. 41, 42. 
Triloculina brongniartii, Parker, Jones, and Brady, 1871, Ann. and Mag. Nat. Hist., ser. 4, vol. viii. 
p. 250, pi. viii. fig. 9. 
Quinqueloculina quinquangularis , Terquem, 1878, Mem. Soc. geol. Fr., ser. 3, vol. i. p. 74, pL xiv. 
figs. 1, 2. 
„ intricata, Id. Ibid. p. 73, pi. xiii. figs. 16-21. 
Of the decorated varieties of Miliolina, those with a surface-ornament of raised lines 
constitute by far the largest proportion. The lines vary in thickness, number, and 
regularity ; in some cases they form very numerous, exceedingly delicate, striae, in others 
they appear as a few stout ribs ; they are usually longitudinal and nearly parallel, but 
often run into sinuate, oblique, zigzag, branching, or reticulated forms. 
Between the delicately striate and the coarsely ribbed Miliolince it is impossible to 
draw any fixed distinction, inasmuch as the thickness and substance of the linear 
ornament varies with almost every specimen ; and it is equally hopeless to attempt to 
sort either the striate or the costate forms into subordinate groups of any real zoological 
value. A few varieties may be disposed of by referring them to the smooth-shelled 
species having the same general contour ; thus, Miliolina Jicliteliana may be regarded as 
the striate variety of the smooth-shelled Miliolina subrotunda; Miliolina macilenta 
stands in the same relation to Miliolina secans, Miliolina insignis to Miliolina trigonula , 
and Miliolina terquemiana to Miliolina tricarinata. Probably this method of treatment 
might be carried further, but there would still remain a large number of specimens having 
linear ornament, but without special morphological characters by which they could be 
associated with any of the well-known unornamented species. As a matter of con- 
venience, therefore, the varieties with fine longitudinal striae not otherwise provided for, 
may be arranged round a single type, such as Miliolina bicornis or Miliolina brongniartii, 
whilst those with stout costae find a central representative in Miliolina pulchella. 
Which of the two former names is adopted for the striate group does not greatly 
matter. If we follow Prof. Williamson’s interpretation of the somewhat enigmatical 
figure in Walker and Boys’ work, and accept the excellent drawings which he gives 
( loc . cit .) in place of it, the trivial name bicornis must take precedence. The Triloculina 
brongniartii of the “ Tableau Methodique,” has a similar linear ornament, but the figures 
in the “ Testaceographia ” on which it was founded are distinctly Quinqueloculine, and 
differ in no appreciable way from those already referred to in Williamson’s monograph. 
The small Triloculine form which d’Orbigny subsequently named Triloculina 
brongniartiana (Foram. Cuba) may belong to the same species, but, if so, the drawing 
represents an immature shell. 
The synonymy which is given above refers only to a few out of a very large number 
of named and figured “ species ” that may properly be included under the term Miliolina 
bicornis. There are certain other striate and costate forms which occur in the collections 
