452 



Messrs. Carpenter, Jeffreys, and Thomson [Nov. 18, 



that there must have been deep seas at all Geological periods, and that the 

 changes which modified the climate and depth of the sea-bottom were for 

 the most part very gradual, — the question naturally arises whether we 

 may not carry back the continuity of the accumulation of the Foraminiferal 

 ooze on some part or other of the Ocean-bed into Geological epochs much 

 more remote, and whether it has not had the same large share in the pro- 

 duction of the earlier Calcareous deposits that it has undoubtedly had 

 in that of the later. Though it is altogether beyond doubt that some 

 beds of Carboniferous Limestone (for example) were simply Coral reefs, 

 covered with waving Conoids and swarming with Brachiopod and other 

 Mollusks, there are other parts of this formation which seem to have been 

 deposited in much deeper waters ; and to these we should be inclined to 

 ascribe a Foraminiferal origin. This hypothesis seems not only probable 

 on general grounds, but is supported by several remarkable facts. It has 

 long been known that certain beds of Limestone of Carboniferous age, in 

 Russia and elsewhere, are almost entirely made up of an aggregation of 

 Foraminiferal shells belonging to the genus Fusulina* ; and Prof. Phillips 

 has described under the name Endothyra Bowtnannif a Foraminiferal type 

 which seems nearly allied to Fusulina, and which he states to occur in great 

 abundance with Texlularia in the Mountain-limestone beds of the North of 

 England. Again, Mr. H. B. Brady has lately shown us, in a thin layer of 

 Clay occurring in the midst of Carboniferous-limestone beds near Newcastle, 

 an accumulation of Arenaceous Foraminifera closely corresponding in type 

 with the Saccammina of Sars, which we found to be abundant, in many of 

 the deeper dredgings of the earlier Cruises, on the eastern border of the 

 North-Atlantic Sea-bed, — To this question, however, we shall recur in 

 the discussion of the General Results of our Deep-Sea explorations. 



90. Thoroughly well satisfied with the success of our third Cruise, both 

 in the confirmation and extension it afforded of the conclusions as to the 

 climate we had ventured to draw from the comparatively few and scanty 

 data we had obtained last year, and in the large mass of Zoological 

 novelties we had collected, we now made for Stornoway, and arrived there 

 on the evening of Wednesday, September 8th. If we had been free to 

 dispose of the ' Porcupine,' we might have taken the opportunity of con- 

 necting the Third with the First Cruise, by exploring the deep bottom to 

 be found about 200 miles to the west of the Hebrides, as far south as the 

 Rockall bank, which had been the northern limit of the First Cruise. 

 But as our vessel was under orders to make a Hydrographic Survey in the 

 neighbourhood of Valentia, as soon as the scientific work of our Expedi- 



* The true zoological position of this Genus, at present only known as a Carboniferous 

 type, has lately been settled by the microscopic examination of the minute structure of 

 the shell of specimens preserved in a clayey stratum of the Carboniferous series in Iowa, 

 U.S., kindly forwarded to Dr. Carpenter by Mr. Meek, of Washington. See the Monthly 

 Microscopical Journal for April, 1870. 



t Proceedings of the Geological and Polytechnic Society of Yorkshire, 1846, p. 227. 



