SYENITE. 



f 747 ] 



SYNDENDRIUM. 



decomposition of the organic matter. 

 Reproduction by fission, and formation of 

 resting spores. (V. Tieghem, Butt. Soc. Bot. 

 J'V. LSSO. l>73; Jn. Mic. Soc. 1881, i. 97.) 



SYENITE. See ROCKS. 



S V M BIOTES = CHOBIOPTES. 



SYMBOLOPH'ORA, Ehr. A genus of 

 Diatomacen. 



Char. Frustules single, disk-shaped, with 

 incomplete septa radiating from the solid 

 angular centre, and intermediate bundles 

 of radiating lines. Marine and fossil. 



S. Trinitatis (PL 25. fig. 6). Valves 

 with a triangular umbilicus, the transparent 

 margins of which are crenulate, the rest 

 of the disk covered with six bundles of 

 very fine radiating lines. Diameter 1-2.30". 

 America. 



S. acufa (PL 18. fig. 54) ; S. micrasterias 

 (fig. 55) ; S. pentas (fig. 56). 



BIBL. Ehr. Her. Berl Ak. 1844, 74 j 

 Kiitz. Sp. Ala. 131. 



SYMPHYOSI'PHON, Kiitz. = Scyto- 

 ncma pt. 



SYM'PLOCA, Kiitz. A genus of Oscil- 

 latoriacese (Confervoid Algae), perhaps not 

 distinct from Symphyosiphon. 



SY r NALIS'SA. A genus of Collemei 

 (Collemaceous Lichens), somewhat resem- 

 bling Lichina, but with open apothecia. 

 (Leighton, Lich. Fl. 13.) 



SYNAP'TA, Eschsch. A genus of ver- 

 miform Echinodermata. 



The species of Synapta, which are not 

 British, are of special microscopic interest, 

 on account of the presence in their skin of 

 remarkable anchor-shaped calcareous spi- 

 cula, the bases of which play in perforated 

 plates. These are situated upon minute pa- 

 pillae of the skin, and serve to aid in loco- 

 motion and adhesion. 



BIBL. V. d. Hoeven, Zool. i. 150 ; Vogt, 

 Zool Briefe, i. 168 ; Quatrefages, Ann. Sc. 

 N. 2. xvii. 19 ; Gegenbaur, Vergl. An. 216 ; 

 Herapath, Qu. Mic. Jn. 1865, 1. 



SYNCEkE'TA, Ehr. A genus of Rota- 

 toria, of the family Hydatinaea. 



Char. Eye single, cervical, rotatory organ 

 furnished with styles; foot forked; jaws 

 each with a single tooth. 



Some of the species are furnished with 

 one or more so-called crests, which in some 

 appear to correspond to the calcar. 



S. baltica (PL 44. fig. 26). Body ovate ; 

 rotatoiy lobes four ; styles four ; a single 

 median sessile crest; marine; length 1-108". 

 Phosphorescent. Three other species. (Ehr. 

 In/us. 436.) 



SYNCIIIT'RIUM, De Bv. & Woronin. 

 A genus of parasitic Unicellular Alga), 

 allied to CHYTRIDIUM, found under the 

 epidermis of the leaves of Taraxacum and 

 Succisa, and composed of aggregated orange- 

 yellow cells, enclosed in an envelope, form- 

 ing sori. 



BIBL. Rabenht. Aty. Hi. 284. 



SYNCORY'NE, Ehr. (par*). A genus 

 of Corynidae (Hydroida). 



BIBL. Allman,.4n. N. H. 1864 ; Hincks, 

 Hyd. Zooph. 48. 



SYNCRYP'TA,Ehr. A doubtful genus 

 of Volvocineae (Confervoid Algaa), composed 

 of organisms consistingof a hyaline spherical 

 gelatinous envelope, enclosing a number of 

 ovate green bodies placed at the periphery, 

 and sending out a pair of free vibratile cilia 

 from the surface of the envelope. Green 

 bodies not attenuated at the posterior ex- 

 tremity ; no eye-spot. S. Volvox (PL 7. 

 fig. 14*6), globe 1-576" in diameter, bodies 

 1-2880" long; freshwater. This object, 

 which we have observed in company with 

 those represented in figs. 14 , 31 and 32 of 

 the same plate, is most probably a young 

 specimen of either Volvox or Pandorina. 

 Kent places it among the Flagelliforna In- 

 fusoria. 



BIBL. Ehr. Inf. 60 ; Kent, Inf. 413. 



SYNCYC'LIA, Ehr. A genus of Diato- 

 maceae. 



Char. Frustules cymbelliform, united in 

 circular bands, immersed in an amorphous 

 gelatinous substance. Marine. 



The nodules appear to be the same as 

 those of Cymbella. 



S. salpa (PL 19. fig. 14). Frustules 

 semiovate, unstriated (ord. ilium.), com- 

 monly six together, united into a ring ; en- 

 dochrome bright green. 



S. quaternaria. Frustules two or four 

 together ; endochrome yellow or reddish ; 

 length 1-860". 



BIBL. Ehr. Inf. 233; Ber. Berl. Ak. 

 1840, 32 ; Kiitzing, Sp. Alg. 61 ; Rabenht. 

 ALg. i. 97. 



SYTTOEN'DRIUM, Ehr. -A genus of 

 Diatomaceaa. 



Char. Frustules single, subquadrangular, 

 destitute of a median umbilicus ; valves 

 unequal, slightly turgid one smooth, the 

 other with numerous spines or little horns 

 branched at the ends, situated upon the me- 

 dian flat portion, the margins being free 

 from them. 



S. diadema (PL 18. fig. 59). Frustules 

 lanceolate ; spines five or six, bifurcate or 



