REPORT ON THE EORAMINIFERA. 
477 
wing, which under exceptional circumstances may attain a width equal to one- 
third the diameter of the body of the shell. The aperture is entosolenian and the 
external orifice generally Fissurine. Reuss has attempted to separate specifically the 
specimens with wide from those with narrow keel, grouping the former under the name 
Fissurina alcita ; but this is a distinction which it is altogether impossible to carry out in 
practice. 
Specimens are occasionally met with in which the keel or wing has a more or less 
serrate edge. Williamson’s figure (Rec. For. Gt. Br., pi. i. fig. 21, a) represents a shell of 
this sort ; and Seguenza gives a drawing of an analogous specimen, under the name 
Fissurina dentata (Foram. Monotal. Mess., pi. i. fig. 55). 
Lagena marginata has been found at the most northerly points at which soundings 
have yet been taken (lat. 83° 19' N.) and thence southward in every sea almost to the 
Antarctic Ice-barrier; and at every depth from the littoral zone down to 3125 fathoms. 
Its earliest appearance, so far as at present known, is in the Chalk of the Island of 
Rligen. It recurs in the Eocene deposits of the Paris Basin (Terquem), in the 
Septaria-clays of Germany (Reuss), the Clavulina-szaboi beds of Hungary (Hantken), 
the Salt-clay of Wieliczka (Reuss), the Miocene and Pliocene of Southern Italy and Sicily 
(Seguenza), and of the south-east of Spain (Parker and Jones), ancl in the Post-tertiary 
formations of England, Scotland, Ireland, and Italy (Shone, Robertson, &c.). 
Lagena marginata, var. seminar ginata, Reuss (PL LIX. figs. 17, 19). 
Lagena marginata, var. semimarginata, Reuss, 1870, Sitzungsb. d. k. Ak. Wiss. Wien, vol. lxii 
p. 468 ; — Schlicht, 1870, Foram. Pietzpulil, pi. iv. figs. 4-6, 10-12. 
Lagena vulgaris, var. marginata (pars), Ry. Jones, 1872, Trans. Linn. Soc. Lond., vol. xxx. p. 55, 
pi. xix. figs. 28, 29 1 
Amongst von Schlicht’s illustrations of Tertiary Foraminifera are two Lagence closely 
resembling that from which the drawing (fig. 17) has been taken. The body of the shell 
is biconvex and surmounted by a long tubular neck, and the angle between the body 
and the neck, on the median line, is occupied by a thin lamelliform wing. To this variety 
the trivial name “ semimarginata” is assigned by Reuss. The shells of recent specimens 
are frequently marked by conspicuously large perforations, and the same is observable 
in one of the original figures above referred to. The test is often, perhaps always, 
furnished with an entosolenian tube as well as the external neck. 
This semi-marginate variety occurs off Prince Edward’s Island, 50 to 150 fathoms ; 
off Heard Island, 75 fathoms ; and at three Stations in the South Atlantic, in mid-ocean, 
depth, 1900 fathoms, 2200 fathoms, and 2350 fathoms respectively. 
Yon Schlicht’s examples were from the Septaria-clays of Pietzpulil in North 
Germany. 
(ZOOL. CHALL. EXP. — PART XXIX. 1884.) 
Y 61 
