SCALES. 



[ 679 



SCHISTOSTEGE.E. 



See also TEST-OBJECTS. 



BIBL. West wood, Intr. fyc., and Brit. 

 Butterflies-, Deschamps, Ann. Sc. Nat. 2. 

 iii. Ill ; Diij. Obs. au Micros. ; Ratzeburg, 

 Die Forst-Insekten ; Siebold, Vergleich. 

 Anat. ; Pigott and M'Intire, M. M. J. 1870, 

 iv. 321 ; ib. 1871, v. 3 j Watson, ib. ii. 73 

 & 314; Anthony, ib. 1872, vii. 1 & 250; 

 M'Intire, M. M. Jn. iii. 1 ; Maddox, M. M. J. 

 v. 33 ; Woodward, ib. v. 149 ; Beck, Qu. M. 

 Jn. 1864, 2 ; Mn. Mic. Jn. iv. 252; Wonfor, 

 Qu. Mic. Jn. 1868, 80 ; Slack, Mn. Mic. Jn. 

 vii. 48 ; Pigott and Beaumont, Proc. Roy. 

 Soc. 1873, 222; Wenham, Mn. Mic. Jn. 

 1874, 75 ; Woodward, ib. xv. 253. 



SCALES OF PLANTS. Under the head 

 of HAIRS, mention has been made of scales 

 (lepides) occurring on the epidermis of 

 plants. They consist of flat, usually more 

 or less circular plates of cellular tissue, the 

 cells presenting a radiated arrangement 

 from the centre, by which they are ordi- 

 narily attached; the margins are usually 

 toothed or fringed more or less regularly by 

 the prolongation of the free ends of the 

 cells. They are closely related to stellate 

 hairs, such as those of ivy, of Deutzia (PL 28. 

 figs. 26*, 27), &c., and may be regarded as 

 more highly developed forms of these. They 

 are particularly remarkable on the epidermis 

 of certain plants which exhibit a kind of 

 scurfy surface, for example 

 the Eleagnaceae (fig. 626), 

 the Bromeliaceoe, some 

 Rhododendra, and the 

 lower surface of the leaves 

 of many ferns ; they must 

 be distinguished in the 

 last case from the ramenta 

 of the stems, which are 

 attached by the base, and scale of the epidermis 

 not by a central pedicle. of Hippophae rham- 



BIBL. See HAD* and a"B,fc- . 

 EPIDERMIS. 



SCAPHID'IODON, Stein. A genus of 

 Hypotrichous Infusoria. Free, convex above, 

 flattened and ciliated below, pointed behind ; 

 mouth with a cylinder of teeth. 8. navi- 

 cula; marine; length 1-240". (Kent, Inf. 

 750.) 



SCARID'IUM, Ehr. A genus of Rota- 

 toria, of the family Hydatineea. 



Char. Eye single, cervical, rotatory organ 

 armed with a hooked bristle in front ; foot 

 forked, very long, adapted for leaping. 



Lateral processes of jaws bifurcate, so as 

 to present two teeth each. 



S. longicaudum (PI. 44. fig. 27). Foot as 



Fig. 626. 



i long as or longer than the body, toes shorter 

 ! than the foot; freshwater, length 1-72". 



BIBL. Ehr. In/us. 439 ; Prit. Inf. 686. 



SCENEDES'MUS, Meyen. A genus of 

 Desmidiaceae. 



Char. Cells fusiform or oblong, arranged 

 side by side in a single row of from two to 

 ten, after division forming two alternating 

 rows ; division oblique ; terminal cells often 

 lunate, or with a bristle at each end. 



Several species (Ralfs). 



8. quadricauda (PI. 14. fig. 50), Cells 

 generally four, oblong, rounded at the ends, 

 in a single row, terminal cells with a bristle 

 at each end. Common ; length of cells 

 1-1120". 



8. obliquus (PI. 14. fig. 51.) Cells ellip- 

 tico-fusiform, after division arranged in two 

 distinct and generally oblique rows, end 

 cells lunate. Length 1-1670". 



S. obtumis (PI. 14. figs. 53 & 54, just after 

 division). Cells three to eight, ovate or 

 oblong, all alike, arranged in one row, or 

 after division alternately in two rows. Com- 

 mon ; length 1-2330 to 1-1960". 



BIBL. Ralfs, Brit. Desmid. p. 189. 



SCEPTRONE'IS, Ehr. A genus of 

 Diatomaceae. Frustules those of Synedra, 

 but the valves cuneiform. Several species, 

 marine and fossil. (Ehrenberg, Ber. Berl. 

 AU. 1844, 264; Grunow. M. M. Jn. xviii. 

 169.) 



SCHIS'MA. A genus of Jungerniannieaa 

 (Hepaticse), founded on a rare British form, 

 8. (Jung.) juniperina, /3. ewopcea, found 

 among rocks on the mountains of Scotland, 

 Ireland, and Wales. It grows 3 to 6" high, 

 and is rarely found in fruit. 



BIBL. Hook. Br. Fl. ii. pt. 1. 124, Br. 

 Jung. pi. 4 ; Ekart, Syn. Jung. pi. 8. fig. 62 ; 

 Endlicher, Gen. Plant. Suppl. 1. No. 472. 



SCHISTOSTE'GE^E. A family of oper- 

 culate Acrocarpous(terminal-fruited) Mosses 

 of gregarious habit. Stem naked below, 

 foliaceous in two manners above ; sometimes 

 frond-like or fern-like, composed of leaves 

 attached vertically and connected at the 

 base, with dense areolations consisting of 

 rhomboidal prosenchymatous pellucid or 

 green cells; sometimes with small leaves, 

 like those of other Mosses, horizontal and 

 arranged quincuncially. All the leaves 

 nerveless and flat. Capsule without an 

 annulus, very minute, globular-oval, with a 

 ! very small convex operculum (figs. 627- 

 630). British genus : 



SCHISTOSTBGA. Calyptra cylindrically 



