288 Proceedings of the Royal Physical Society. 



we meet with spiculse 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 poly- 

 thalamia. The beautiful siliceous polycistince 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 poly- 

 tludamia shell. 



The deposits now forming at the bottom of the North 

 Atlantic, therefore, differ notably from the latter, in contain- 

 ing so many jpolytJialamice. 



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. Further 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 



