A U R 



[42] 



A U T 



Terebratulse by British authors, 

 but they have acute, not perforated 

 beaks." Sir R. Murchimon. Sil- 

 urian System. 



ATTENUATED, (attenuaius, Lat. attenue, 

 Fr.) Thin; slender; tapering. An 

 epithet for a leaf tapering at one or 

 both extremities. 



AU'GITE. (av^rj, Gr. splendour.) A 

 mineral of a dark green, brown, or 

 black colour, found in volcanic 

 rocks. It is the Pyroxene of Haiiy, 

 the Paratoma augit of Mohs, and 

 the augit of Werner. Its fracture 

 is conchoidal and uneven. It gene- 

 rally crystallizes in six or eight- 

 sided prisms, terminated by dihedral 

 summits. It is commonly attracted 

 by the magnet. Scarcely fusible 

 by the blow-pipe. With borax it 

 . melts into a yellowish glass, which 

 while hot appears red. There are 

 many varieties of augite, as the 

 Diopside, Musite, Alalite, Sahlite, 

 Pyrogome, Fassaite, Malacolite, 

 Common Augite, Conchoidal Augite, 

 Granular Augite, Coccolite and 

 Amianthus. Augite consists of 

 silica 52, lime 13, protoxide of 

 iron and manganese 16, magnesia 

 10, alumina 9. 



ATTGI'TIC PO'EPHYEY. A rock with a 

 dark grey, or greenish, base, con- 

 taining crystals of augite and 

 Labrador felspar. 



ATJLO'POHA. The name given by 

 Goldfuss to a genus of corals. Pour 

 species are described as found in 

 the Wenlock Limestone. Three of 

 them have been named by Goldfuss, 

 namely, A. conglomerata, A. serpens, 

 and A. tubseformis ; the fourth A. 

 consimilis has been described and 

 thus named by Mr. Lonsdale. 

 Species of the genus Aulopora are 

 found in other strata. 



ATJ'EATED. 



1. Resembling gold. 



2. Eared ; having ears, as in the 

 scallop-shell. 



ATJEE'LIA. The first change of the 

 eruca, or maggot, of any kind of 



insect; a chrysalis, having a golden 

 hue, previous to its becoming the 

 perfect insect. 



AU'EICLE. (auricula, Lat.) 



1. That part of the ear which is 

 prominent from the head. 

 1. A cavity of the heart. The 

 heart is divided into four cavities, 

 or chambers, namely, two auricles 

 and two ventricles. 



ATJ'RICLED. Having ears; having 

 appendages resembling ears; ap- 

 plied to leaves when they are 

 furnished with a pair of leaflets, 

 generally distinct, but sometimes 

 joined with them. 



AUEI'CULA. An ovate or oblong pyra- 

 midal marine univale, with the 

 spire extruded : the opening entire, 

 oblong, and narrowed upwards; the 

 columella plicated, with different 

 plicaB in the opposite lip. Lamarck 

 has placed those shells whose open- 

 ings are entire, but whose columella3 

 are plicated, under this genus, 

 Auricula. Parkinson. Possil auri- 

 culaa occur in the chalk marl and 

 in the Shanklin sand. Seventeen 

 species have been recorded \)j 

 Deshayes : of many species re- 

 corded from the neocomian rocks of 

 Prance, the genus is doubtful. 



ATJEI'CTJLATE. Ear-shaped. 



ATJ'EIFOEM. (from auris and forma, 

 Lat.) Having the form of an ear; 

 in the shape of an ear; the haliotis 

 is an example. 



ATT'STEAL. } (australis, Lat. austral, 



AU'STEINE. j Pr. australe, It.) South- 

 ern ; southward. 



AUTO'MALITE. (Octahedral corundum 

 of Mohs. Spinelle zincifere of 

 Haiiy. The Automolith of Werner ; 

 sometimes also called Gahnite, from 

 Gahn, its discoverer. The name 

 automalite was given to it by 

 Eckeberg.) A variety of corundum 

 containing oxide of zinc. It occurs 

 imbedded in talc, and associated 

 with lead-glance. It is crystallized 

 in regular octahedrons, or in tetra- 

 hedrons with truncated 



