REPORT ON THE FORAMINIFERA. 
659 
Of the biconvex varieties there is a small but very interesting series, separated by 
Reuss from the rest of the genus under the name Siphonina, characterised by an 
exaggerated development of the lipped orifice, and by a tendency to marginal decoration. 
It is difficult, perhaps impossible, to distinguish these forms as a generic group, by any 
sufficiently precise or constant characters, from the more normally constructed shells, 
although they appear to present well-marked minor features. Their typical structure 
is best exemplified in Truncatulina reticulata, which, nevertheless, is an exceedingly 
variable organism ; and to a less degree in Truncatulina soluta and Truncatulina 
echinata. 
Occasionally the stouter varieties of Truncatulina have limbate sutures, but with this 
exception the shell is rarely endowed with external ornament of any kind ; sometimes, 
however, the surface is beset with raised tubercles, irregularly disposed, and one or 
two species already referred to display a fringe-like marginal extension of the chamber- 
walls. 
Truncatulina refulgens, Montfort, sp. (PI. XCII. figs. 7-9). 
“ Hammonia Balanus seu Bcilanoidea,” Soldani, 1789, Testaceographia, vol. i. pt. 1, p. 58, 
pL xlvi. figs, nn, oo. 
Gibicides refulgens, Montfort, 1808, Concliyl. System., vol. i. p. 122, 31 e Genre. 
Truncatulina refulgens, d’Orbigny, 1826, Ann. Sci. Nat., vol. vii. p. 279, pi. xiii. figs. 8-11 ; — 
Modele, No. 77. 
„ „ Parker and Jones, 1865, Phil. Trains., vol. civ. p. 382, pi. xvi. fig. 19. 
„ „ Brady, 1865, Nat Hist. Trans. Northd. and Durham, vol. i. p. 105, 
pi. xii. fig. 9, a.-c. 
This is a stoutly-built, thick-shelled variety, the test of which, in well-developed 
examples, is bell-shaped or subconical, and the sutures complanate or but little depressed 
externally. It is isomorphous with Pulvinulina micheliniana, with which species it has 
sometimes been confounded. 
Truncatulina refulgens is moderately common over a considerable area of the North 
Atlantic, between lat. 47° and lat. 62° N. On this ground it has been collected at twelve 
Stations, the depths of which range from 45 fathoms to 2400 fathoms. It occurs also in 
the Mediterranean and the Adriatic. Avoiding the tropics, it reappears in the temperate 
zone of the southern hemisphere, — off the Cape of Good Hope, 150 fathoms ; on the east 
coast of Australia ; and at several points on the western shores of Patagonia, — at depths 
of 50 to 250 fathoms. 
Less is known of its distribution as a fossil. It has, however, been obtained from the 
Pliocene beds of Southern Italy (Seguenza) ; from the Red Crag of Essex (Jones, Parker, 
and Brady) ; from the Glacial-clays of Norway (Crosskey and Robertson) ; and from the 
Post-glacial deposits of the north-east of Ireland (Wright). 
