140 Guide to the Special Collections. 



GALLERT iYOva various localities, a large trunk of a tree from the Purbeck 

 ^- beds, Isle of Portland, and several Sigillaria stc ms from the Coal- 

 measures, are arranged along the centre of this Gallery. 



DEEP-SEA DEPOSITS. 



Table-case In the centre of Gallery X, there has been temporarily placed 



centre o^f ^ ^^^® containing a large series of deep-sea deposits, obtained during 



Gallery X. the cruise of H.M.S. ''Challenger," which have been examined 



and described by Dr. John Murray, F.R.S., and the Eev. A. 



Eenard. They consist of nodules of manganese, associated with 



bones and teeth of fishes ancT^tacea, and also a large series of 



Foraminifora, etc, ; they have a peculiar interest as giving us a clue 



to the mode of formation of ancient geological marine deposits 



containing similar remains to those now met with in dredging 



in the abysses of the Atlantic and Pacific Oceans. 



case 16. 



HISTOmCAL AND TYPE COLLECTIONS, STRATI^ 

 GRAPHICAL SERIES, ETC. 

 ^ yt'^^ In Gallery XI has been arranged, in seventeen cases, a series 

 of nine collections of historical and palaeontological interest, 

 bearing upon the early history of the British Museum and the 

 study of Geology and Palaeontology in this countiy. 

 Sir Hans Taking the exhibition cases in chronological order, the eailiest is 

 Co°kction ^^^ Sloane Collection. This is the most ancient portion of the 

 1753. Geological series, having formed a part of the Museum of Sir Hans 



Table-^ Sloane, Bart., F.R.S., acquired by purchase for the nation in 1753. 

 The geological collection is stated to have consisted "of what 

 by way of distinction are called extraneous fossils, comj)rehending 

 petrified bodies, as trees, or parts of them ; herbaceous plants 

 [the botanical and zoological specimens are now preserved in 

 their respective Departments], animal substances," etc. ; and 

 reported to be "the most extensive and most curious that ever 

 was seen of its kind." Until 1857 the fossils and minerals 

 formed one collection, so that a large part of the Sloane Col- 

 lection consisted probably of mineral bodies, and not organic; 

 but in any case only about 100 specimens of invertebrate fossils 

 can now be identified with certainty as forming part of the 

 original Sloane Museum. Each specimen in the Sloane Collection 



