AULISCUS. 



BACILLUS. 



AULIS'CUS, Ehr. A genus of fossil 

 Diatomaceae. 



Differs from Eupodiscus in the processes 

 being more solid and less fragile, and in the 

 markings of the valves consisting of wavy 

 festooned strife, in some resolvable into 

 dots, in others not. But the genus seems 

 unnecessary. 



Eupodiscus sculptus (PL 16. fig. 31) would 

 form a species of Auliscus. 



Auliscus pruinosus, PL 18. fig. 60. 



BIBL. Ehrenberg, Ber. d. Berl. Ak.-, 

 Bailey, Smiths. Contrib. 1854; Greville, 

 (Monogr), Micr. Tr. 1863, p. 36; ibid, 

 (neiv spec.}, 1863, p. 75; 1864, pp. 82, 88 ; 

 1865, p. 5 ; 1866, p. 6 ; Rabenhorst, Flor. 

 Alg. p. 320. 



AULOCOM'NIUM, Schwsegr. A genus 

 of Mosses. See MNIUM. 



AVAN'TURINE. 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 

 with numerous minute crystals of metallic 

 copper distributed through it. These crys- 

 tals ore mostly in the form of triangular or 

 hexagonal plates, the angles sometimes cu- 

 riously prolonged or beaked. 



It forms a beautiful microscopic object, 



It was originally manufactured at Venice, 

 and the process kept secret. But MM. 

 Fremy and Clernandot have shown that it 

 may be prepared by heating glass with prot- 

 oxide of copper and iron scale (protoxide 

 of iron) ; the latter reduces the protoxide 

 of copper by combining with the oxygen so 

 as to form the peroxide. 



BIBL. Wohler, Chem. Gaz. i. ; Fremy and 

 Clemandot, /. c. iv. 



AVENEL'LA, DalyelL A genus of In- 

 fundibulate Polyzoa, of the suborder Cyclo- 

 stomata, and family Vesiculariidae. 



Distinguished by the thread-like, nearly 

 simple base ; the large, scattered, solitary, 

 slightly contracted and curved cells ; and 

 the 20 to 24 tentacles and small gizzard. 



The single species, A. DalyeUii (fusca), 

 brown, occurs matted with foreign matters ; 

 cells about 1-16" long. On Sertulariae, f rom 

 deepish water. 



BIBL. Dalyell, Anim. of Scotland, ii. 65 ; 



Gosse, Mar. Zool. ii. 21 ; Hincks, Poh/z. 526. 



m AVICULA'RIA. A term applied to the 



'birds'-head processes of the Polyzoa. See 



POLYZOA. 



AZOLLA, Kaulf. A genus of Marsile- 

 aceae or Rhizocarpese, consisting of a few 

 species of small floating plants, occurring 

 in Australia and throughout America. The 

 mode of reproduction is evidently analogous 

 to that of Salvinia ; but its development has 

 not yet been fully examined. 



BIBL. R. Brown, Flinders's Voyage, ii. 

 App. p. 611 ; Meyen, Nova Acta, xviii. 

 p. 507 ; Griffith, Calcutta Jn. of N. Hist. v. 

 p. 227 ; Mettenius, Linncea, xx. p. 259, 1847 

 (Ann. des Sc. Nat. 3 ser. xi. p. 111). 



B. 



BACILLA'RIA, Gmelin. A genus of 

 Diatomaceae. 



Char. Frustules bacillif orm, at first united 

 transversely into a straight tabular series, 

 subsequently forming oblique series; valves 

 with a longitudinal row of puncta, and an 

 excentric keel ; marine. 



B. paradoxa (PL 16. fig. 14, and PL 18. 

 fig. 17). Front view of frustules linear, 

 rectangular, valves linear-lanceolate ; length 

 1-220". (a, front view of oblique series of 

 frustules ; b, valve.) 



B. socialis, Greg., and B cursoria, Donk. 



BIBL. Kiitz. Sp. Alg. and Bacill. ; Smith, 

 Brit. Diat. ii. 8; Rabenhorst, Fl. Alg. i. 

 165. 



BACIL'LUS, Cohn. A genus of Schi- 

 zomycetous Fungi. 



Char. Filaments very minute, straight, 

 slender, short or of moderate length, rigid 

 or flexible, moveable or not, joints indis- 

 tinct ; never found naturally in the Zooglcea- 

 form. 



B. suUilis (PI. 7. fig. 18, PL 1. fig. 19). 

 Filaments very slender, elongate; joints 

 single or many, with a cilium at each end ; 

 movement flexuous, active. In stagnant 

 waters, &c. It forms Pasteur's butyric fer- 

 ment, and the hay-bacillus ; length 1-5000" 

 and upwards. 



B. anthracis. Like the last, but general- 

 ly longer, motionless ; length 1-6000" and 

 upwards. In the blood and tissues of cattle 

 and sheep, the horse, &c., producing the 

 disease termed Anthrax, or splenic malig- 

 nant fever, the Charbon of the French, the 

 Milzbrand of the Germans, also the human 

 malignant pustule, and the wool-sorters' 

 disease. 



B. ulna (PL 7. fig. 20). Filaments join- 

 ted, thick and rigid, movement rotary and 

 progressive. Warming describes cilia as in 



