of Edinburgh, Session 1881-82. 
657 
In addition to the above the following were observed : — 
Globigerina bulloides. 
Globigerina injlata. 
Orbulina universa. 
Pulvinulina micheliniana (one). 
Salpre, Sagittse, Schizopods, Amphipods, larvae of Membranipora , 
Lamellibranch, Gasteropod and Echinoderm larvae, Peridinium 
tripos , and Coccospheres. 
5. Dredgings , Trawlings , and Soundings. —For convenience of 
reference and comparison we divide these into (a) those on the 
plateau surrounding North Rona and Sulisker, (b) those in the 
warm area, (c) those in the cold area, and (d) those on the Wyville 
Thomson ridge. 
(a.) On the Plateau surrounding North Rona and Sulisker. 
(1) Soundings . — A great many soundings were taken on the 
plateau which surrounds North Rona, and between it and the Butt 
of Lewis and Cape Wrath. The depths were from 30 to 80 fathoms, 
the average being about 50 fathoms. 
The bottom was sometimes a fine calcareous sand, sometimes a 
quartz sand, and sometimes a fine gravel. These varieties of deposits 
occurred without any apparent relation to depth. Generally the 
particles were more or less rolled, and all the materials collected on 
this plateau out to the 100 fathom line, gave the impression that 
they were often set in motion and frequently sorted by the action of 
waves and currents. None of the soundings indicated the presence 
of mud or argillaceous matter. 
The calcareous particles were composed of broken and rolled 
fragments of mollusc shells, polyzoa, Annelid tubes, echinoderms and 
foraminifera. 
The sandy particles were chiefly rounded fragments of quartz, with 
some pieces of mica, hornblende, and feldspar. 
The gravel was composed of rolled pieces of the older rocks, 
as amphibolic gneiss, Cambrian sandstone, diorite, and pieces of 
jasper. 
The following were the percentages of carbonate of lime in four 
of these soundings : — • 
^ See Mr. H. B. Brady’s Report. 
