ATAXOPHRAGMIUM. 



L 86 ] 



AULACOSIRA. 



Herm.) (PL 6. 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 vis- 

 cera indistinctly visible through the skin. 



A. Bonzi is semitransparent, yellowish, 

 with some brown ; parasitic in the shell of 

 the freshwater mussel. 



Murray states that Arrenurm viridis is 

 the male of Atax histrionica. 



BIBL. Walckenaer, Apteres, iii. (Gervais) ; 

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

 Sc. N. 2 se*r. i. ; Koch, Deutschl. Crust., &c. ; 

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

 1. 1871, 55) ; Murray, JEcon. Entom. 154. 



ATAXOPHRAG'MIUM, Reuss. The 

 Buliminae with arenaceous shells come un- 

 der this denomination. 



BIBL. Reuse, 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 flakes and molecules, 

 plates of cholesterine and granules of carbo- 

 nate of lime. 



ATHY'RIUM, Roth. A subgenus of 

 Aspkniwn (Polypodiaceous Ferns). To this 

 belongs the lady-fern, A. Filix-fcemina, for- 

 merly known as &&Aspidium and a Lastrcea. 



AT'OM A, or Astoma, Latr. = TBOMBI- 

 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, Carpologia, iii. p. 104. 



ATRACTOB'OLUS, Tode. JFormerly 

 described as a genus of Nidulariacei (Gaste- 

 romycetous Fungi), is merely the egg of a 

 Raphianathus. 



ATRACTONE'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 Atractylidae. 



Char. Polypes naked, borne on a stolon, 

 erect, funnel-shaped, with a conical probos- 



cis, surrounded by a simple whorl of filiform 

 tentacles. 



A. arenosa. Surface sanded. On stones, 

 and roots of Laminaria. 



BIBL. Hincks, Hydr. 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 

 (Termitidae). 



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. pukatorius (book-mite) is very com- 

 mon in dried collections of plants, old books, 

 &c., which form its food. It is about 1-^0" 

 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 Psocus 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, Entom. Text-book, 368 ; 

 id. Introdnct. $c., ii. 1 7 & 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. 



ATTHEYEL'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. 



AULACODIS'CUS. See EUPODISCUS. 



AULACOG'RAPHA, Leighton. A ge- 

 nus of Graphideae (Lichenaceous 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. N. H. xiii. p. 389, 

 pi. 7, 1854 ; Lichen-Fl. 427. 



AULACOSI'RA. See MELOSIRA. 



