ATAXOPHRAGMIUM. 



[ 86 ] 



AULACOSIRA. 



Herm.) (PI. 6. fig. 14). Body dark red, paler 

 in frunt of the eyes, a square black spot iu 

 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 vis- 

 cera indistinctly visible through the skin. 



A. Bonzi is semitransparent, yellowish, 

 with some brown ; parasitic iu the shell of 

 the freshwater mussel. 



Murray states that Arrenurus viridis is 

 the male of Atax histrionica. 



BiBL. Walckenaer, ^4y>f('/rs, iii. (Gervais) ; 

 Hermann, 3Iem. Aptcrol. ; Duges, Ann. d. 

 Sc. N. 2 ser. i. ; Koch, Deutschl.Crust., &c. ; 

 Claparede, Studien an Acariden {Ann. N. H. 

 1. 1871, 5.5); Murray, Econ. Entom. 154. 



ATAXOPIIRAG'MIUM, Reuss. — The 

 Buliminse with arenaceous shells come un- 

 der this denomination. 



BiBL. Reuss, Sitz. Ak. Wien. xliv. 383. 

 ATHERO'MA.— Atheromatous deposits 

 consist of globules of oil of the most varied 

 sizes, frequently exceedingly minute, mixed 

 with albuminous matter in the form of 

 amorphous masses or fiakes and molecules, 

 plates of cholesteriue and granules of carbo- 

 nate of lime. 



ATHY'RIUM, Roth.— A subgenus of 

 A^pleniumCPo\y\wd.ia.CQO\xs Ferns). To this 

 belongs the lady-fern, A. Filix-fa'mina, for- 

 merly known as an Aspidium and a Ladrcea. 

 AT'OMA, or Astoma, Latr.= Thombi- 

 DIUM, pt, 



ATRAC'TIUM.— A supposed genus of 

 Stilbacei (Hyphomycetous Fungi), charac- 

 terized by its fusiform elongated spores, 

 but now believed to be a state of some 

 Nectria. 



BiBL. Tulasne, Carpohgla, iii. p. 104. 

 ATR ACTOB'OLUS, Tode. — Formerly 

 described as a genus of Nidulariacei (Gaste- 

 romycetous Fungi), is merely the egg of a 

 Raphiqnathns. 



ATRACTOXE'MA, St. —A genus of 

 Flagellate Infusoria. 



Char. Free, fusiform, flagellum single ; 

 oral aperture connected with the contractile 

 vesicle, nucleus central. 



A. teres (PI. 53. fig. 8). Fresh water. 

 BiBL. Kent, Infus. p. 373. 

 ATRAC'TYLIS, Wright.— A genus of 

 marine Polypes, of the order Hydroida, and 

 family Atractylidie. 



Char. Polypes naked, borne on a stolon, 

 erect, funnel-shaped, with a conical probos- 



cis, suiTomided by a simple whorl of filifoi-m 

 tentacles. 



A. arenosa. Surface sanded. On stones, 

 and roots of Lnminaria. 



BiBL. Hincks, Hi/dr. Polypes, p. 87. 



AT'RICHUM, Palis.— A genus of Moss- 

 es, forming a subdivision of Polytri- 



CHUM. 



BiBL. Wilson, Bryol. Brit. p. 202. 

 ATRO'PIA (Atropine). See Alkaloids. 

 AT'ROPOS, Leach.— A genus of Hyme- 

 nopterous Insects, of the family Psocidae 

 (Termitidse). 



Characterized by the long setaceous an- 

 tennae, which have more than ten joints, 

 the absence of wings, the eyes of moderate 

 size, and the three-jointed tarsi. 



A. pulsatorius (book-mite) is veiy com- 

 mon in dried collections of plants, old books, 

 &c., which form its food. It is about 1-20" 

 long, of a dirty-white or yellowish colour ; 

 head oblong; joints of antennae elegantly 

 striated transversely ; mandibles horny and 

 toothed ; abdomen oblong-ovate, depressed ; 

 posterior femora thickened. 



The allied genus Psociis has the head 

 broad, and the posterior margin of the fore 

 wings with three or four cells. The species 

 are found upon old palings, the bark of 

 trees, &;c. 



BiBL. Westwood, Eyitom. Text-book, 308 j 

 id. Introduct. 6,-c., ii. 17 & 20. 



AT'THEYA, West.— A genus of Diato- 

 maceae. 



Char. Frustules compressed, annulate ; 

 valves elliptic lanceolate, with a median 

 longitudinal line ; angles spinous. 



A. decora (PI. 51. fig. 39). Druridge 

 Bay. 



BiBL. Micr. Tr. viii. p. 152. 



ATTHEY'EL'LA, Brady.— A genus of 

 Copepodous Entomostraca, allied to Can- 

 thocamptus. 



2 species ; fr. water. 



BiBL. Brady, Copepoda {Ray Soc.). ii. 58. 



AUGITE. See Rocks. 



AULACODISCUS. See Eupodlscus. 



AULACOG'.RAPHA, Leighton.— A ge- 

 nus of GraphidetB (Lichenaceous Lichens), 

 fouudod on the species Atdacoyrapha {Ope- 

 (jrapha) elvyans, Sm., distinguished by the 

 peculiar furrows of. the projier mai'gins sur- 

 rounding the di>ks of the lirellae. Grows on 

 the bark of trees. 



BiBL. Leitrliton, Ann. N. II. xiii. p. 389, 

 pi. 7, 1854; i/c/t«i-i^/. 427. 



AULACOSI'RA. See Melosika. 



