MICROCYSTIS. 



[ 503 ] 



MICROTIIECA. 



blasfu.-i, Kiitz?). — A gemi9t)f OscillatoriacefB 

 (Coiifervoid Alg« ), with frond.s I'oriuing- 

 strata on moist gTouiid, patlis, imul, &c. 

 These phints may be described as bundles 

 of Os(//A//o;vrt-fiLiments enclosed in a com- 

 mon ^n'lalinous sheath, which is simple oi' 

 irregularly dichotomously branched, and 

 forms twisted interwoven masses. The 

 structure of the filaments appears to bo 

 identical witli that occurring in Oscilla- 

 TORiA, described under that head ; the fila- 

 ments oscillate : the mode of origin of the 

 enclosing sheath is obscure ; but it would 

 appear to be formed of the gelatinous half- 

 dissolved outer membranes of the enclosed 

 filaments. No formation of spores or goni- 

 dia has been described. M. repens, Harv. 

 (PI. 8. tig. 9a, the open end of a sheath), 

 is very common on damp paths, kc, its 

 sheaths are branched ; M. aiiguiformis, 

 Harv., occurs on the mud of brackish 

 pools; its sheaths are said to be simple. 

 31. gracilis, Hrissall, said to be found in 

 similar situations, has no character attached 

 to it. 



BiBL. Harvev, Mar. AUj. 227, pi. 26 D ; 

 Plu/c. Br. pl.24ij; Hassall, ^/(7. 260, pi. 70; 

 Kiitz. Tab. Fhyc. i. pis. 54-58. 



JMICROCYSTIS, Kiitz.— A genus of 

 Palmellaceffi (Confervoid Algae), composed 

 of crowded minute spherical cells, enclosed 

 in a common envelope, forming- solid fami- 

 lies. M. protoc/enita (PL 3. fig. 12), bluish 

 green, in long-kept water. 



BiBL. Kiitz. Sp. Alfj. 208; Tub. Phyc. 

 pis. 8, 9 ; Rabenh. Alg. ii. 51. 



MICROGLE'NA, Ehr.— A genus of In- 

 fusoria, family Monadina, E. 



Char. Tail absent ; body truncated in 

 front, with a single flagelliform filament ; 

 one or two red eye-spots present. Fresh- 

 water. 



Probablv the spores of Algae. 

 M. punkifera (PL 31. fig. 43a). Body 

 yellow, ovate, subconical, attenuate poste- 

 riorly, two red eye-spots accompanied by 

 a blackish frontal spot ; length 1-620". 



M. monadina (PL 31. fig. 436). Body 

 ovate, equally rounded at both ends, bright 

 green ; eye-spot red and single ; length 

 1-1150 to 1-020". 



BiBL. Ehr. Infus. 25 ; Kent, Inf. 403. 

 MICROGONID'IA. See Macrogoxidia. 

 MICROGRO'MIA, Hert.— A genus of 

 ReticiUarian Rhizopoda. The pseudopodia 

 of different individuals unite, so as to pre 

 duce colonies. 

 X. Slip pi. 1.) 



(Her twig, Arch. mile. An. 



MICROTI ALO' A, Kiitz.— A genus of Pal- 

 melLicea; (Confervoid Alga;), consisting of 

 microscopic gelatinous patches, floating in 

 water, crowded with minute green gonidia. 

 M. Ichthyohlabe (quite distinct from Cla- 

 THROCYSTis) occurs in IMtain ; and Has- 

 sall's Sorospora virescetis belongs here. Pro- 

 bably a Chhrococcus. 



BiBL. Kiitz. Sp. Alfl. 207; Tab. Phyc. 

 pis. 6, 7 ; Ilassall, Alg'. 326 ; Rabenh. Aly. 

 iii. 60. 



MICRO'MEGA, Ag., = Schizonema pt. 



MICROM'ETER. See Introduction, 

 p. xxviii, and Measurement. 



MICROBE Pt A, Lev.— A genus of Sphjs- 

 ronemei (Stylosporous Fungi), of which 

 one species is described as British, M. dru- 

 pacearum {Cenanyium Cerasi, junior, Fr., 

 Spha>ria dubia, Pers.), growing on dead 

 branches of the cherry-tree. It forms 

 whitish tubercles which split the bark trans- 

 versely, composed of somewhat cylindrical 

 conceptacles, conjoined at the base, the 

 white mealy ostiole projecting; the linear 

 spores are yellowish and curved at the 

 apex. 



BiBL. Berk, and Broome, Ann. N. IT. 

 2 ser. V. 380 ; Leveille, Ann. Sc. Nat. 3 s(5r. 

 V. 283 ; £r. Flora, ii. pt. 2, 211. 



mCROP'ORA, Gray,= Membranipora 

 pt. (Hiucks, Polyz. 173.) 



MICROPOREL'L A, Ilincks, = Lepralia 

 pt. (Hincks, Poh/z. 204.) 



MI'CROPYLE (of Animals). See Ovum. 



MICROSCOPE.— The first Section of 

 the Introduction consists of remarks upon 

 the microscope and microscopic apparatus. 



MICRO-SPECTROSCOPE. See Spec- 

 troscope. 



MICROS'PORA, Thuret,= Conferva pt. 



MI'CROSPORES.— The small kind of 

 spores produced by Lycopodiacete and Mar- 

 sileacese in contradistinction to megasporea 

 or macrospores. When sown, they pro- 

 duce sperm-cells and spermatozoids. 



MICROTHAM'NION, Niig. — A genus 

 of Chaetophoracese. 



Char. Filaments much branched, rigid, 

 jointed, narrow; joints longer than broad, 

 slightly tumid. Propagation by zoogonidia. 

 Freshwater. 



BiBL. Rabenh. Alg. iii. 365. 



MICROTIIE'C A,"Ehr. —A marine organ- 

 ism of doubtfid nature. 



It consists of yellow, flattened, rectan- 

 gular (side view) bodies, with four equi- 

 distant spines projecting from each end; 

 the colour arises from the contents ; no 



