283 
1914-15.] Chalk Boulders from Aberdeen, etc. 
numerous, one or two small pieces of Bryozoa ; Globigerinse, Textularians, 
and other forms occur ; the rock also contains sponge spicules, having the 
silica of their walls replaced by calcite. A few small mineral grains occur 
throughout the section, but this chalk from ocular observation does not 
convey the impression that much terrigenous matter is present. Analysis 
confirms this. The residue contained quartz grains, besides Ammodiscus 
and fragments of Rhizammina. There were also many pieces of silicified 
vegetable matter similar to that met with in the specimens from Belhelvie. 
21. — Faroe Channel. Two-thirds of the recognisable ingredients are 
coarse shell fragments, chiefly of the same irregular and ragged type, and 
large pieces of Bryozoa. There are two or three Textularians, but the few 
Foraminifera which occur are chiefly Rotaline forms; there are no 
Globigerinse. Mineral grains are abundant and coarse ; they include quartz 
and felspars, but mica was not detected. A greenish material allied to 
glauconite is present ; it has formed within the hollows of shell fragments 
and foraminiferal cells, but only partially filling them. The matrix of this 
specimen is coarsely granular calcite. 
The next four specimens, G 17, 18, 19, and 20, consist entirely of 
fragments of Bryozoa, and in their general characters bear the closest re- 
semblance to the Bryozoan limestone of the Upper Senonian of Denmark. 
The last specimen, which I believe to be a chalk, consists almost entirely 
of Inoceramus prisms and fragments of shell showing prismatic structure 
set in a calcareous paste. The prisms are, however, those of the Upper 
Chalk, long and narrow, retaining their width for about two-thirds of their 
length, then tapering so irregularly as in some cases to give the appearance 
of constriction to a blunt point. In their general contour they are less 
sharply angular than those of the Lower and Middle Chalk. In the section 
are one or two Globige rinse, one well-marked Rotaline form, and a single- 
celled Foraminifer. 
Of this series G I to G 12 (omitting G 6) are chalks differing entirely 
from the Belhelvie series. They are all very pure chalks ; in one (G 3) 
analysed 99'2 per cent, was soluble in the acid. The presence of ‘‘ spheres ” 
and the short broad Inoceramus prisms, together with the larger fragments 
showing the prismatic structure, the striking similarity of G 3 to 
nodules of the Melbourn Rock, and of G 12 to the structure of the chalk 
at the base of the zone of R. Guvieri of the south of England, suggests 
that the whole of them, though differing slightly from each other, may 
belong to the Middle Chalk. The presence, in three out of four analyses, 
of vegetable matter identical with that found in many of the Belhelvie 
boulders may be taken as evidence of the continuity of the deposit, even 
