SCHIZONEMA. 



[ 682 ] 



SCHIZOXYLON. 



incomplete, and it appears that mere pro- 

 ducts of decomposition of higher organized 

 bedies, and crystalline precipitates and crys- 

 talloids of carbonate of lime have been in- 

 cluded among them. 



Some are recognized as the zymotic 

 agents in the production of disease, as Ty- 

 phus and Typhoid Fever, Splenic Fever, c. 

 Five genera are admitted : Micrococcus, cells 

 globular, indefinite ; Sarcina, cells in cubes ; 

 Bacterium, cells or joints single or in twos, 

 short; Spirillum, fibres undulate, short, in 

 flexible; Spirillum, fibres spiral, flexible ; 

 Spirochtste, fibres helical, long. 



See the genera, and the BIBL. of those 

 articles. 



SCHIZONE'MA, Ag. A genus of Dia- 

 tomacese. 



Char. Frustules short, straight or sigmoid, 

 resembling those of Navicula, aggregated in 

 longitudinal rows in a filiform, simple or 

 branched, slender and lax gelatinous frond. 

 Marine. 



Sporangia or sporange-like bodies (sper- 

 matia) filled with frustules, occur within the 

 substance of the sheaths. This form, of 

 brood-sporangia, as they might be called, 

 appears to resemble that occurring in the 

 Desmidiacete (PI. 10. fig. 3 A). 



The species in which the frustules are 

 contained in simple tubes, form the genus 

 Colhtonema ; those in which the tubes are 

 enclosed in outer tubes, the genus Micro- 

 mega (PL 17. fig. 8). Rabenhorst includes 

 all in the genus Schizonema. 



Species very numerous ; Smith describes 

 seventeen as British. 



8. Dillwynii (PI. 19. fig. 12). Frond hya- 

 line, tufted, wavy, lubricous, bright green, 

 much branched ; end branches short, nume- 

 rous, patent, attenuate, and somewhat acute ; 

 frustules towards the base of the frond 

 remote and scattered, towards the ends 

 crowded, oblong-truncate in front view; 

 valves lanceolate, 1-1020'' in length. 



BIBL. Kiitzing, Bacitt. Ill, 8p. Alg. 97 ; 

 Smith, Br. Diat. ii. 71 ; Rabenhorst, Alg. 

 i. 265. 



SCHIZONEU'RA, Hartig. A genus of 

 Aphi dae . 6 species, including Aphis laniyera ; 

 on the apple, black currant, fir, elm, plum, 

 &c. (Buckton, Aphid., Ray Soc. iii. 88.) 



SCHIZOPHYL'LUM, Fr. A genus of 

 Agaricini, characterized by the gills splitting 

 along the edge and becoming revolute. 



S. commune is one of the commonest exotic 

 Fungi, and is rare in this country, except 

 introduced accidentally on foreign wood. 



BIBL. Fr. Obs. i. 103 ; Sow. 1. 183 ; Grev. 

 t. 61 ; Berk. Eng. Fl. v. 130 ; Cooke, Handb. 

 16. 



SCHIZOPOREL'LA, Rmcka, = Lepralia 

 pt. Orifice of the cells semicircular or 

 rounded, inferior margin with a notch. 

 Several species. (Hindis, Polyzoa, 237.) 



SCHIZ'OPUS, Clap, and Lach. A genus 

 of Hypotrichous Infusoria. 



Char. Marginal cirri absent, frontal cirri 

 and uncini present, also dorsal styles. 1 sp. 

 S. norvegicus, (PI. 52. fig. 20); marine. 

 (Claparede et Lachmann, Inf. 182.) 



SCHIZOSFPHON, Kt. Bodies as in 

 Stichotricha, but situated in the ends of a 

 branched zoary. S. socialis ; freshwater. 

 (Kent, Inf. 778.) 



SCHIZtoSI'PHON, Kiitz. A genus of 

 Oscillatoriaceae (Confervoid Algae), contain- 

 ing Calothrix scopulorum, fascicidata, and 

 perhaps other species of Harvey's ' Manual.' 

 Another British species has also been de- 

 scribed by Caspary, S. Warrenite (PI. 8. 

 fig. 13) ; this extends over large surfaces of 

 maritime rocks, in dull blackish-green tufts 

 of variable size, from 1-4 to 1-2" in thick- 

 ness. The erect filaments are fastigiately 

 branched (), the basal cell of the branches 

 broader and hemispherical (c) ; ochreal 

 sheaths obscure (b), frequently exhibiting a 

 spiral-fibrous structure in decay (d, e) ; apices 

 of the branches much attenuated. 



BIBL. Kiitz. Sp. Alg. 326, Tab. Phyc. ii. 

 pi. 47 ; Harvey, Mar. Alg. 224 ; Caspary, 

 Ann. N. H. 2. vi. 266, pi. 8 ; Rabenhorst, 

 Alg. ii. 232. 



SCHIZOTHE'CA, Hincks, = Lepralia 

 pt. Two species. (Hincks, Polyzoa, 283.) 



SCHI'ZOTHRIX, Kiitz. A genus of 

 Oscillatoriaceae (Confervoid Algae), of which 

 two British species, growing over maritime 

 rocks, have been described. 



S. Cresivcllii(P\. 8. fig. 17). Tufts 1-2 to 

 3-4" high, olive-coloured ; filaments curled, 

 1-3600" in diameter at the base, 1-12000" at 

 the summit, in twisted bundles, penicillately 

 corymbose above. 



S. Smithii (Coleonemd), Thw. Stratum 

 dense, dirty red ; filaments closely entwined, 

 more or less laterally concreted, 1-9600 to 

 1-8400" in diameter'; sheaths lax, multipli- 

 cate, the internal prolonged and exserted. 



BIBL. Kiitz. Sp. Alg. 320, Tab. Phyc. ii. 

 pi. 40 ; Harvey, Mar. Alg. 223, pi. 26 B, 

 Phyc. Brit. pi. 190. 



SCHIZOX'YLON,Pers. A genus of PI*, 

 codei (Lichenaceous Lichens). One species ; 

 on oaks, rare. (Leighton, Lich. Flora, 390.) 



