SHELLS. 



They are much ufed in France for this purpofe ; and Mr. 

 Reaumur treats of their effefts in fertihzing the earth 

 very fullyi concluding his ufeful account of thefe fub- 

 itances by obferving, that it is much more eafy to account 

 for the manner of their afting upon land, than for the 

 manner of their coming where they are found. It has been 

 the favourite fyitem of our Dr. Woodward, that all thefe 

 (hells were the remains of the 'univerfal deluge, whicJi 

 having overflowed the whole earth, might eafily leave them 

 in all places ; but Mr. Reaumur has much more rationally 

 accounted for their coming to thofe parts of France, where 

 they are found at this time m fuch vaft abundance, by care- 

 fully tracing the courfe of the beds of them, fo far as known 

 there, and ealily proving that all that extent of country, 

 under which they are found, may have been once overflowed 

 by the fea without a deluge ; it being the very track that a 

 large body of waters, let in at one part of the kingdom, 

 mull have taken, in order to getting out at another. Mem. 

 de I'Acad. Par. 1720. 



Shell, Arabian, a name given by fome to a fpecies of 

 porcelain (hell, not becaufe it is found on the coalt of Ara- 

 bia, but becaufe its lines and variegations are fuppofed to 

 reprefent the figures of Arabic characters. 



Shell, Aurora, a very remarkable fpecies of (hell-fifli, 

 found in cabinets of the curious. It is of the figure of 

 a bird, having a head, wings, and tail, and is of a flame- 

 .colour ; it owes much of its beauty, however, to art and 

 accident ; the Ihell is an oyfter of a peculiar variation of 

 figure from the common one ; the head of the bird is the 

 cardo or hinge ; the wings are the body of the fhells ; and 

 the tail is a peculiar procefs, like that of the marteau, only 

 fingle. 



It is naturally of a dufl<y brown on the outfide, and 

 pearly within, but when its rough coat is taken off, it 

 appears of this beautiful flame-colour. 



Shell, Caterpillar. See Turbo. 



Shell, Centre, a name given to the balanus marinus, a 

 kind of fea-(hell of the multivalve kind, with an open 

 mouth, frequently found fixed to the bottoms of fliips, 

 and other things covered with fea-water. See Balanus and 



CONCHOLOGY. 



Shell, Chalice, or Cup-Jhell, a fpecies of the balanus. 

 See Balanus. 



Shell, China-letter, a name given by many t© that fpe- 

 cies of chama, ulually called by authors the chama Arabica. 

 It is of a pale brownifh ground, and is variegated with 

 a great number of black lines, which are as flcnder as 

 the Itrokes of a pen, and are of fuch odd figures, that they 

 reprefent fome of the Arabic, or, as others fancy, Chinefe 

 charaflers. See Chama. 



Shell, Croivn Imperial, a fpecies of the voluta. 



Shell, Dog-tooth, a ipecies of dentalis. 



Shell, Ear, See Auiiis. 



Shell, Guinea, the Enghfh name for a very beautiful 

 variegated fpecies of voluta, called by the French la /pe- 

 culation. 



Shell, Heart. See Cakdium, under Conchologv. 



Shell, Helmet, the name of a kind of murex, of which 

 there are fevcral fpecies. They all approach fomewhat to- 

 wards a triangular figure, and are free from any long fpines. 



Shell, Leopard, the Englidi name of the parduii, a kind 

 of voluta, fo called from its fpots refembliug thofe of a 

 leopard. There are three kinds of this, one fpotted with 

 black, another with yellow, and another witli red. 



Shell, Leveret, a name given by many to a Ipecies of 

 porcelain-fhell, rei'embling a young hare in colour. 



Shell, Lightning, a name given by fome authors to a 

 fpecies of murex, with variegations on its body, refembling 

 the pidures we commonly fee of flallies of lightning. 



Shell, Map, the name given by fome to a peculiar fpe- 

 cies of porcelain-lhell, the figures on which reprefent the 

 lines on a map. 



Shell, Needle. See Centkonia and Needle. 



Shell, Noah's Ark. See Noah. 



Shell, Oyjler. See Oyster. 



Shell, Old Wife, the name given by fome to that 

 fpecies of chama, which the French alfo have called •oicHe 

 ridee. 



Shell, Onion, a fpecies of oyfter. 



Shell, Pipe. See Entalium. 



Shell, Saddle, the name of a fpecies of oyfter, which 

 in fome degree reprefents a faddle in its fliape. 



Shell, St. James's, a name given by writers on fliells to 

 a very beautiful fpecies of variegated peften. 



Shell, Si. Michael's, a name given by authors to a fpe- 

 cies of peften, or fcallop-fliell. It is of a bright yellow 

 colour. 



Shell, Scorpion, the name of a fpecies of murex, very 

 much approaching to the nature of the fpidcr-fhell. This 

 is a common fliell in cabinets ; it is of a yellow colour, and 

 very deeply ridged, and full of tubercles ; there arife from 

 the lip of the (hell five large ipines, or, as they are ufually 

 called, fingers, and two others, which are very much bent, 

 the one from the head, the other from the tail : thefe are very 

 elegantly radiated with white, and a fine violet colour on the 

 lips. 



Shell, Screw. See Turbo. 



Shell, Small-pox, a name given to a remarkable kind of 

 concha venerea, or porcelain-lhell, the protuberances on the 

 furface of which are fuppofed to reprefent the puftules of 

 the fmall-pox. There are two fpecies of this fliell, the one 

 white, with flattifli protuberances, the other greenifli, with 

 more elevated ones. 



Shell, Snake, the name given by many to that beautiful 

 fpecies of porcelain-fhell, the fpots of which reprefent thofe 

 of a fnake's flcin. 



Shell, Spider. See Aranea. 



Shell, Straiuberry, a name given by colleflors of (hells 

 to a very beautiful fpecies of cordiformis, fpotted with fmall 

 round red fpots. 



Shell, Sivallow, a name given by authors to a fpecies 

 of oyller, which in fome degree reprefents the figure of a 

 fmall bird flying. 



Shell, Tiger, the name of a fpecies of porcelain, or 

 concha venerea, fuppofed to reprefent the fpots on a tiger's 

 fkin. 



Shell, Toe. See Polmcii'es. 



Shell, Tortoife. See 'I'oktoise. 



Shell, Trumpet. See TuuMiET. 



Shell, Turban. See Turban. 



Shell, Turnip. Tliis is a fpecies of fea-fliell, by others 

 called the radijh fliell ; it is cxaftly of the fliape of a tur- 

 nip, and is of the dolium, or concha globola kind. Thofe 

 who have called it the radifli fliell, allude to the great 

 black round-rooted radifli, not to our common radifli. 



Shell, Turtle, the name of two fpecies of (hells. See 

 MuuEX and Voluta. 



Shell, in Agriculture, a term applied to a hard, and as 

 it were (lony covering, with which certain fubflancis and 

 animals are defended, and thence in the latter c;i(e called 

 fliell-fifli. It is obferved that the vait beds of foflile (hells 

 found at great depths in the t.-u-th, aa well as thofe found 



lying 



