ASTOMUM, 



[ 



] 



AVANTURINE. 



In similar situations, rather more common. 

 Agaricus Ly coper dioides. Sow. 



BiBL. Hook., Br. FL ii. part 2. 322; 

 Sowerby, Fungi, t. 279; Stm^m, Deutschl. 

 FL iii. t. 26; BuUiard, Herb. t. 166, 516, 

 fig. 1. 



ASTOMUM, Hampe.— A genus of Bru- 



Fig. 49. 



Fig. 50. 



Astomum subulatum. 



A leaf showing the cellular 



structure. 



Magnified 40 diameters. 



Astomum altemifolium. 



Section of sporange. 

 Magnified 40 diameters. 



chiacese (Acrocarpous Mosses), including 

 some of the Phasca of Linnaeus, &c. 



1. A. subulatum, Hmp. = PAascMm subu- 

 latum, L. (fig. 49). 



2. A. altemifolium, Ilmp. = P^. altemi- 

 folium, Dicks, Crypt, (fig. 50). 



3. A. nitidum, Hmp.^PA. axillare, Dicks. 

 BiBL. See MuscACE^. 



AT AX, Duges. — A genus of Arachnida, of 

 the order Acarina, and family Hydrachnea. 



Char. Body ovoid ; a genital fissure bor- 

 dered by two plates, upon each of which 

 are three transparent, rounded tubercles ; 

 anterior coxse posteriorly in contact in the 

 median line, wedging the labium between 

 them anteriorly; the two groups of posterior 

 coxse distant; fourth coxa very broad, in 

 contact with the third throughout its whole 

 length ; palpi with the fourth joint very 

 long, attenuate, slightly excavated towards 

 the end to receive the fifth joint in a state of 

 extreme flexion; fifth joint forming a pointed 

 claw ; mandibles consisting of a thick body, 

 cut off" obliquely like the point of a pen pos- 

 teriorly, truncate anteriorly, and terminated 

 by a large, strong and slightly curved claw ; 

 labium oval, concave and bifid. 



Several species, of various brilliant colours. 



A. histrionica {Hydrachna histrionica, 

 Herm.) (PI. 2. fig. 14). Body dark red, paler 

 in front of the eyes, a square black spot in 

 front of them ; dorsally marked with longi- 

 tudinal converging striae ; five black spots 

 on the anterior portion of the ventral surface ; 

 palpi and legs blackish green. 



The black spots are produced by the 

 viscera indistinctly visible through the skin. 



BiBL. Walckenaer, Apteres,'m. (Gervais); 

 Hermann, Mem. Apterol. ; Duges, Ann. d. 

 Sc. nat, 2 ser. i. ; Koch, Deutschl. Crust., 

 &c. 



ATHEROMA. — Atheromatous deposits 

 consist of globules of oil of the most varied 

 sizes, frequently exceedingly minute, mixed 

 with albuminous matter in the form of amor- 

 phous masses or flakes and molecules, plates 

 of cholesterine and granules of carbonate of 

 lime. 



BiBL. Works on Medicine and Surgery ; 

 Lebert, Phys. Pathol. ; Bennett, Edinb. 

 Monthly Journ. vii. ; Wedl, Grundz. d. 

 path^ Hist. ; Rokitansky, Ueber einig. d. 

 wichtig. Krankh. d. Arterien. 



ATRACTOBOLUS, Tode.— Described as 

 a genus of Nidulariacei (Gasteromycetous 

 Fungi), but now stated to be the egg of a 

 Rophignathus. 



ATROPIA (Atropine). See Alkaloids, 

 p. 25. 



AULACODISCUS. See Eupodiscus. 



AULACOGRAPHA, Leighton.— A genus 

 of Graphidese (Gymnocarpous Lichens), 

 founded on the species Aulacographa {Ope- 

 grapha) elegans, Sm., distinguished by the 

 peculiar furrows of the proper margins sur- 

 rounding the disks of the lirellae. Grows on 

 the bark of trees. 



BiBL. Leighton, Ann. of Nat. Hist. 2nd 

 ser. xiii. p. 389. pi. 7. 1854. 



AULACOSIRA. See Melosira. 



AULOCOMNIUM, Schwaegr. See 

 Mnium. 



AURICULARTNL— A tribe of Hymeno- 

 mycetous Fungi characterized by bearing 

 their basidiospores on the surface of papillae 

 situated on the under or outer side of a 

 tubular, cup-shaped or funnel-shaped spo- 

 range. See Hymenomycetes and Basi- 

 diospores. 



AVANTURINE.— A mineral composed 

 of silex, with numerous minute scales of 

 mica interspersed through its substance, or 

 traversed in all directions by minute fissures 

 or cracks ; giving it an elegant sparkling or 

 iridescent appearance. 



Artificial Avanturine consists of glass, 



