222 Part ITI.— Eleventh Annwal Report 
be quite sufficient to account for the difference in depth between the 
different soundings. The depth of the west portion of the loch was not 
tested, but the west end is probably comparatively shallow, if one may 
judge by the numerous islets at that end, and by the contour of the land 
contiguous to this part of the loch. 
Specific Gravity and Temperature of the Bottom Water. 
The self-locking water-bottle,* which was let down and touched bottom 
at 145 fathoms, as already stated, was when hauled up found to be per- 
fectly closed, and filled with water mixed with impalpable mud. This 
mixture was emptied into a sufficiently large vessel, and when the mud 
had subsided the supernatant water was run off and tested by one of the 
set of hydrometers used on board the ‘Garland.’ The specific gravity 
registered by this hydrometer was 1007:9; temperature of water at the 
time the specific gravity was taken, 13-9° C. (57:2° F.) The temperature 
of the water at the bottom of the loch, taken with a ‘Negretti-Zambra’ 
deep-sea reversing thermometer, was 42° F.; at 100 fathoms the tem- 
perature was 49°6° F.; and at the surface, 57°7° F. The water, as in 
the case of many Highland lochs, was of a brown peaty colour. 
Tnwertebrate Fauna. 
The bottom mud brought up by the dredge and by the water-bottle at 
Station IV. was carefully examined, with the result that no living organism 
could be detected in it; a considerable portion of it consisted of fragments 
of Entomostracan tests that formed a distinct layer on the surface of the 
mud after it had been allowed to subside; it thus resembled very closely 
the mud from the bottom of Loch Ness. The loch was tow-netted in 
various places from Brinacory eastward to the head of the loch. The 
tow-net collections were chiefly made at the surface or at a depth of a few 
fathoms. On one or two occasions, however, the tow-uet was attached to 
the dredge and lowered to a depth of from 50 to 100 fathoms. Ento- 
mostraca were found to be abundant at and near the surface, but were 
much fewer at 50 and 100 fathoms: the grouping of the species, 
however, appeared to vary very little in the surface and deep-water 
gatherings. A few gatherings were made by dragging the tow-net 
through the weeds in the shallow water at the head of the loch, and also 
close inshore at Brinacory—on the north side of the loch, near Brinacory 
island. Two days were devoted to the examination of Loch Morar, but 
the weather was not very favourable. On the first day there was almost con- 
tinuous rain; the first part of the second day was rather better, but a 
smart westerly breeze sprang up shortly after noon, which caused the 
water to become choppy, and made rowing more exhaustive and difficult. 
Mr Anderson Smith accompanied us the second day, and but for his 
assistance and encouragement our success, small though it may be, would 
have been less. 
Pelagic Entomostraca, though abundant in Loch Morar at the time of 
my visit, included comparatively few species, viz., two (or three) species 
of Copepoda and five of Cladocera; on the other hand, the bottom material, 
though comparatively poor in number of specimens, was rich in species, 
especially of Cladocera,—the number obtained in the bottom gatherings 
include eight species of Copepoda, five of Ostracoda, and sixteen of 
Cladocera. The apparent scarcity of the Ostracod group is noteworthy, 
and is probably attributable to non-suitability of habitat. The physical 
* For description of this water-bottle, see Sith Anaucl Report of the Fishery 
dared for Scotland, part iii, p. 616, pl. x. (1888), 
