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THE VOYAGE OE H.M.S. CHALLENGER. 
in the absence of any appendicular tongue to the aperture — a character which may be 
accidental, and in any case one to which very little importance can be attached. 
Biloculina depressd, var. serrata, nov. (PI. III. fig. 3, a.b.c.). 
“ Frumentaria Lenticulce ,” Soldani, 1798, Testaceograpliia, vol. ii. p. 54, pi. xix. fig. o. 
A variety presenting the same general characters as Biloculina depressa , but having 
a dentate peripheral edge, the teeth being angular and the points directed outwards. 
In deep water the margins of the large Biloculince frequently assume a dentate form, 
though the peculiarity is one that varies very much in degree. Well-marked specimens 
have been noted at seven Stations (Challenger and “ Porcupine”) in the North Atlantic, 
and at four Stations in the South Pacific, the depth ranging from 580 to 1750 fathoms. 
Biloculina depressa , var. murrhyna, Schwager (PI. II. figs. 10, 11). 
Biloculina murrliyna , Sclivvager, 1866, Novara-Exped., Geol. Theil, vol. ii. p. 203, pi. vi. 
fig. 15, a-c. 
This is a mere varietal modification of Biloculina depressa, distinguished by having 
two angular or pointed projections on the peripheral edge near the base of the shell, 
placed symmetrically a little distance apart. 
Memoranda have been kept of the occurrence of similar bicaudate specimens at four 
Stations ; one in the North and one in the South Atlantic, one in the North and one in 
the South Pacific, at depths ranging from 1180 to 1900 fathoms. 
The fossil specimen figured by Dr. Schwager is from a late Pliocene deposit in the 
Nicobar Islands. 
Biloculina Icevis, Defrance, sp. (PI. II. figs. 13, 14). 
Pyrgo Icevis, Defrance, 1824, Diet. Sci. Nat., vol. xxxii. p. 273 ; atlas, pi. lxxxviii. fig. 2. 
,, ,, Blainville, 1825, Malacologie, p. 482, pi. lxii., bis. fig. 2.' 
Biloculina Icevis, d’Orbigny, 1826, Ann. Sci. Nat., vol. vii. p. 298, No. 8. 
The little shell, figured by Defrance and Blainville under the name Pyrgo Icevis, 
differs from most of its congeners in being to some extent bicarinate. The line of union 
between each fresh chamber and the preceding one is a little within the periphery of the 
latter ; so that while the margin of the last segment forms the periphery of the test, the 
free edge of the penultimate makes a parallel border, though it does not project so far. A 
character of this sort naturally varies a good deal in different specimens. It is well shown 
in fig. 14, which closely resembles Blainville’s drawing ; not so well in fig. 13, of which 
the general contour of the shell in other respects approaches that of Biloculina depressa. 
Biloculina Icevis occurs at two Stations in the North Atlantic, at depths of 1215 
and 390 fathoms respectively, and in shallow water, Humboldt Bay, Papua. 
The specimens originally described by Defrance were from the Paris Tertiaries. 
