288 Froceedings of the Royal Physical Society. 
we meet with spiculae of sponges. There are also present 
the broken, and, in some cases, perfect valves of the coscino- 
discus, but any other organisms are too undecided to pro- 
nounce upon. 
The sample from 700 fathoms is still less abundant in such 
objects. 
Deep sea soundings have now been effected in various 
parts of the world. Professor Bailey examined specimens 
brought up in Lat. 56" 46' N., Long. 168° 18' E., the depths 
being respectively 900, 1700, and 2700 fathoms. 
They yielded a variable proportion of mineral matter, 
diminishing as the depth increased, a quantity of the silice- 
ous shields of diatoms including coscinodiscus and numerous 
spiculse, but not a fragment of any of the calcareous jpoly- 
thdlamia. The beautiful siliceous jpolycistince were also 
observed. 
A specimen brought up by Brook's sounding-rod in the 
coral sea, in Lat. 13° S., Long. 162° E., from the reported 
depth of 2150 fathoms, afforded many spiculse of sponges, a 
very few diatoms including the coscinodiscus, some polycis- 
tince, and a very few fragments and only one perfect jpoly- 
thalamia shell. 
The deposits now forming at the bottom of the North 
Atlantic, therefore, differ notably from the latter, in contain- 
ing so many polythalamice. 
Perhaps at some future date we may be able to discover 
some connection between the various minute forms and the 
localities at which they occur, as well as the currents flowing 
in the waters below which they are met with. At present 
we must content ourselves with accumulating observations. 
IV. Furtlier Notice of the Herring and Sprat Fishery of the Firth of 
Forth. By George Logan, Esq., Convener of the Society's Committee 
on Marine Zoology. 
In continuation of the remarks upon the herring and 
sprat fishery of the Firth of Forth, submitted to the Society 
in the Eeport of their Committee on Marine Zoology, on 
24th January last, the Convener pursued a careful exami- 
nation of the fish brought to market daily, through the 
