ASS 



[39] 



AST 



consisting of inferior limestones 

 and shale. Dr. Mantell states the 

 Ashburnham beds to consist of a 

 series of highly ferruginous sands, 

 alternating with clay and shale, 

 containing ironstone and lignite; 

 and shelly limestone, alternating 

 with sandstone, shale, and marl, 

 and concretional masses of grit. 

 The organic remains consist of ferns 

 and carbonized vegetables ; cypris ; 

 shells of cyclas and cyrena; and 

 lignite. 



A'SHLAR. A name given to freestone 

 as it is taken from the quarry. 



ASIPHONIBRANCHIA'TA. In De Bj^in- 

 ville's system, the second order of 

 the class Paracepholophora Dioica, 

 comprising the genera Goniostomata, 

 Cricostomata, Hemicyclostomata, 

 Ellipsostomata, and Oxystomata. 



A'SPHALT. 1 (a<r0a\TosGrr. bitumen, 



ASPHA'LTOS. > asphalte, Fr.) A bit- 



ASPHA'LTTTM. ) uminous substance, 

 found abundantly on the shores of 

 the Dead Sea; in the island of 

 Trinidad, in China, America, and 

 various parts of Europe. Its colour 

 is brown or black; it is lighter than 

 water, and easily soluble in naphtha, 

 but quite insoluble in water. Frac- 

 ture conchoidal. Brittle. Feels 

 smooth, but not unctuous. Does 

 not stain the fingers. On the sur- 

 face of the Dead Sea it is found 

 floating in a state of liquidity, but 

 exposure to the air soon renders it 

 hard. It melts easily when heated, 

 and, if pure, burns without leaving 

 any ashes. 



ASPEBG'ILLTJM. A genus of bivalve 

 shells of the order tubicola. The 

 Serpula penis of LinnaBus. 



ASPIDOBHY'NCHUS. The name given 

 to a fossil Sauroid fish from the 

 lime stone of Solenhofen. An ex- 

 ample of this is given by Professor 

 Buckland in his Bridgewater Trea- 

 tise, pi. 27 a, fig. 5. 



ASSA'Y. The operation of determining 

 the proportion of precious metal 

 contained in any mineral or metal- 



lic compound, by analyzing a 

 portion thereof. 



A'STACTD. | The craw-fish, or lobster; 



A'STACTTE. j a genus of the family 

 Macroura ; it is divided into four 

 sections, each consisting of many 

 subgenera. The lobster, crab, craw- 

 fish, prawn, and shrimp are in- 

 cluded. 



A'STACTJS. (from a^ra^o?, Gr. astacus, 

 Lat.) The lobster or craw-fish. 



ASTA'COLITE. (from a<rraKo<? and \iOo? f 

 Gr.) Fossil or petrified craw- fish, 

 or lobster. 



ASTA'ETE. (from the Sidonian god- 

 dess ; the Crassina of Lamarck.) A 

 genus of bivalve shells; equi valve, 

 inequilateral, thick, compressed ; 

 hinge with two large diverging 

 teeth in the right valve, one in the 

 left ; ligament external. The spe- 

 cies are numerous, more especially 

 the fossil ones ; forty- six are enu- 

 merated in Morris's catalogue of 

 English fossils, and many others 

 have not been described. Lycett. 



ASTE'EIA. fasterias, Lat. asUrie, Fr.) 

 A variety of sapphire, or bastard 

 opal. 



ASTE'BIA. (from a<nrfp, Gr. a star.) 

 The star-fish, or sea-star, a genus 

 of animals, class Yermes, order 

 Mollusca. These animals have 

 their mouth in the centre, and. 

 placed downwards ; from their 

 bodies five or more rays, or arms, 

 are given off, furnished with nu- 

 merous retractile tentacula. They 

 have the power of reproducing 

 their rays if destroyed. They are 

 all inhabitants of the sea, and they 

 are frequently found fossil, in great 

 perfection, in the chalk. Some- 

 remarkably fine impressions have 

 been discovered in flint. The whet- 

 stone of Devonshire affords similar 

 remains. Linnaaus has placed them 

 in the order Pedicellata, class Echi- 

 nodermata. 



Two species of this genus of 

 radiata have been found fossil in 

 the chalk, one of which has been 



