RUELLIA. 



[ 072 ] 



SALICOENARIA. 



BiBL. Decaisne, Ann. Sc. Nat. 2. xii. 

 251 ; Ann. N. H. vi. 257. 



RUEL'LIA. — A genus of Acaiitliaceous 

 plants. The testa of the seed of JRnellia 

 formosa exhibits a peculiar kind of Haxr, 

 *(P1. 28. %. 21). 



RUST OF Plants. See Blight. 



RUTILA'RIA, Gr.— A genus of Diato- 

 macese. Frustules compressed, forming a 

 short filament ; valves elliptical, elevated at 

 the angles, with a central nodule, termina- 

 ting in two short processes ; margin spinous. 

 3 species ; in the Barbadoes deposit. (Cire- 

 ville, Tr. Mic. Soc. 186G, 124.) 



RYE. — The grain of Secak cereale. See 

 Starch. 



RYLAND'SIA, Gr. & Ralfs.— A genus 

 of Diatomacete. Frustules simple, disk- 

 shaped, areolar ; valves with two opposite 

 smooth raJ^s, dilated at their base, not 

 i-eaching the centre. R. hiradiata, Barba- 

 does deposit. (Greville, Qu. Mic. Jn. 1861, 

 67.) 



RYTIPHLCE'A, Ag.-A genus of Rho- 

 domelaceae (Florideous Algse), containing 

 fovu" British species, mostly common, having 

 pinnately branched, filifoi'm or compressed 

 fronds, transversely striate and reticulated ; 

 the articulate axis is composed of a circle of 

 large elongated tubular cells surrounding a 

 central cell, the whole enclosed by a kind 

 of rind of several layers of small coloured 

 cells. Colour mostlv dull red or brown. 

 Fronds from 2" to 4" or 6" high. Cem- 

 midia scattered on the ramules of some 

 plants ; antheridia tufted in the same situ- 

 ations on others ; and tetrahedral tetra- 

 spores occur imbedded in a double row in 

 stichidia, borne on distinct plants. R. trinas- 

 truidcs (PI. 4. fig. 11). 



BiBL. Harvey, Mar. Alrj. 80 ; Grev. AJg. 

 Br. ; Derbes and Solier, Ann. Se. Nat. 3. 

 xvi. 275 ; Thuret, ibid. 4. iii. 20. 



S. 



SACCAM'MINA, Sars. See Littjolida. 



SACOOG'YNA.— A genus of Junger- 

 mannieae (Ilepaticoe) founded on Jumjer- 

 mminia viiicidosa of Linnteus ; it is re- 

 markable on account of the subteiTaneous 

 fleshy perianth, in which character and in 

 habit it is allied to Cab/jw(/eia. It is found 

 among mosses, especially in alpine districts. 



BiBL. Hook. Rr.Fl. ii. pt. 1. 121; Br. 

 Junr/. pi. GO ; Ekart, Syn. Jun/f. pi. 1. fig. 6; 

 Eudlicher, Gen. PL Supp. 1. iNo. 472-23. 



SAC'CULUS, Gosse.— A genus of Rota- 

 toria, of the family Ichthydina. 



Char. Eye single, frontal ; body free fi-om 

 hairs, and mthout a foot ; rotatory organ a 

 simple wreath ; alimentary canal very large ; 

 jaws set far forward, apparently consisting 

 of two delicate unequal lateral pieces, and 

 a slender central portion, very evanescent ; 

 eggs attached behind after deposition. 



*S'. viridis. Length 1-150" ; freshwater. 



BiBL. Gosse, Ann. N. H. 1851, viii. 198. 



SADLE'RIA, Kaulf — A genus of Blech- 

 neae (Polypodiaceous Ferns). Two species; 

 arborescent; Sandwich Islands. (Hooker, 

 Syn. Fil. 187.) 



SAGENEL'LA, Brady. —A simple, 

 branchmg, Arenaceous Foraminifer, at- 

 tached to NuUipores, forming a network 

 with its anastomosing branches (1-200" to 

 1-65" in diameter). Admiralty Islands. 

 (Brady, Qu. Jn. Mic. Sci. n. s. xix. 41.) 



SAGO. — Farinas obtained from a variety 

 of tropical plants are known by this name'; 

 but the true East-Indian sagoes are ex- 

 tracted from the central part of the trunks 

 of Palm-trees belonging to the genus Sayns, 

 natives of the Moluccas. In PI. 46. fig. 23, 

 is figured the starch of a sago obtained' 

 from the Museum at Kew; but it is un- 

 certain whether this is the produce of a 

 Sayus; its grains resemble those of some 

 East-Indian Arrow-roots (PI. 46. fig. 18). 

 See Starch. 



SAGRI'NA, D'Orb. (Sagraixa, Reuss). 



See UviGERINA. • 



SAL A 'CIA, Lamx. — A genus of La- 

 foeidse, Hydi-oid Zoophytes. 



Char. Stem erect, composed of aggregated 

 tubes, branching, rooted. Cells cylindrical, 

 sessile, without operculum, aduate fur the 

 greater part of their length, on all sides of 

 stem and branches in regular longitudinal 

 rows. Ovicells scattered on the stem and 

 branches. Polypes long, cylindrical, with 

 a conical proboscis. 



'S'. abietina. Deep water oft" Northumber- 

 land coast. (Hincks, ^yr/. Zoojih. 211.) 



SALICINE. — The alkaloid of the willow 

 and poplar. 



The so-called circular crystals of this 

 substance (PI. 39. fig. 9) form a beautiful 

 polarizing object. The largest crystals are 

 obtained bv fusion. 



SALICURNA'RIA, Cuv.-A genus of 

 Chcilostomatous Polyzoa. 



Char. Surface divided into rliomboidal 

 or hexagonal spaces by ridges sarn.undiug 

 the cells : avicularia disposed irregularly. 



