BEL 



[52] 



B E 



it resembles an elongated conical 

 stone, of a crystalline, radiated 

 structure, and is generally of a 

 brown colour : some limestones on 

 the Continent of Europe are almost 

 wholly composed of them. Ink- 

 bags, resembling those of the Loligo, 

 have been found in connection with 

 belemnites in the lias at Lyme 

 Regis; these, in some instances, 

 are nearly a foot long, and prove 

 that the animal to which they 

 belonged must have been of great 

 size. The fact of these animals 

 having been provided with a reser- 

 voir of ink, affords an a priori 

 probability that they had no ex- 

 ternal shell, but recent discoveries 

 decide the question, two specimens 

 having been found each containing 

 an ink-bag within the anterior 

 portion of the sheath ; and, con- 

 sequently, all the species of belem- 

 nites may henceforth with certainty 

 be referred to a family in the class 

 of Cephalopods. Eighty-eight 

 species of belemnites have already 

 been discovered; and the vast 

 numerical amount to which indivi- 

 duals of these species were extended, 

 is proved by the myriads of their 

 fossil remains that fill the oolitic 

 and cretaceous formations. Buck- 

 land, aJcewell, Mantell. 



BELE'HNO-SE'PIA. The name proposed 

 to be given by Professor Buckland, 

 in concurrence with M. Agassiz, to 

 a new family of cephalopods, to 

 which family may be referred 

 every species of belemnites. 



BELLE'ROPHON. An extinct genus of 

 mollusca, belonging to the order 

 Heteropoda, found in the Silurian 

 and Carboniferous rocks, the shell 

 of which was without chambers. 

 De Montfort placed the bellerophon 

 among chambered shells; De Blain- 

 ville assigned their position next to 

 Bulla. 



BELO'PTERA. A genus of fossil fishes 

 established by Deshayes, of which 

 no recent species is known ; Cuvier 



considered that the remains thus 

 placed in a distinct genus were 

 merely portions of some sepia. 



Bi' VALVE, (bivalvis, Lat. bivalve, Er.) 

 An animal having two valves, 

 shells, or shutters, as the oyster, 

 muscle, &c. 



BE'MBRIDGE BEDS. These are of the 

 Eocene period, and consist of the 

 upper marls, the lower marls, the 

 oyster-bed, and the limestone bed. 



BE'RENICTA. The name given by La- 

 mouroux to a genus of fossil corals. 

 One species, B. irregularis, is found 

 in the Wenlock limestone, at Dud- 

 ley. It is thus described "opening 

 of the cells round, distant where 

 the surface is flat, generally rear 

 together where it is uneven ; more 

 or less regularly disposed from a 

 centre. Murchison. Silurian Sys- 

 tem. 



BEBG'MANNITE. A mineral so called 

 in honour of the celebrated chemist 

 Bergmann. It occurs massive and 

 is of a greenish or greyish white : 

 it has been found in Norway. 



BE'RYL. (leryllus, Lat. leryl, Er.) 

 A crystallised compound of the 

 earth glucina with silica, alumina, 

 lime, and oxide of iron. The beryl 

 is a gem, or precious stone, of the 

 genus emerald, but less valuable 

 than the emerald. It differs from 

 the precious emerald in not possess- 

 ing any of the oxide of chrome, 

 from the presence of which the 

 emerald obtains its splendid green 

 colour. The aqua-marine is a 

 variety of the beryl, having a more 

 transparent texture. The beryl is 

 of a greyish-green colour, blue, 

 yellow, and sometimes nearly 

 white; occasionally different colours 

 appear in the same stone. Beryl is 

 found in many parts of the world, 

 but the finest specimens are 

 brought from Siberia. Vauquelin 

 first discovered the earth glucina 

 from analyzing the beryl. Some 

 mineralogists consider beryl and 

 emerald to differ merely in their 



