MYXORMIA. 



[ 531 ] 



NAIDINA. 



bark externally, ct'lltilar internall}^ by means 

 of filaments conjoined into membranous 

 layers. 



Reticidana. Peridium indeterminate, 

 simple, nalced, fugacious, bursting iiregu- 

 laily, laying- bare branched, reticulated ad- 

 nate filaments. 



Li/cogala. Peridium detemiinate, com- 

 posed of a double membrane, membranous, 

 somewhat warty, persistent, bursting at tlie 

 summit. Fihimeiits adnate on all sides of 

 the peridium. 



BiBL. Schmitz, Lhtn-cpa, xvi. 188 ; De 

 Bary, Die Mt/cefozoa, 18G4; Plofmeister, 

 P/ii/s. Bot. ii. 2\)o ; Cienkowsky, Jahr. trhs. 

 Hot. iii. 325, 400 ; Kent, InK'klO ; Sachs, 

 Bot. 26o ; Cooke, Myxomyc. 1877. 



MYXOR'MIA, Berk, and Br.— A genus 

 of Coniomycetes, containing one species, M. 

 atroL-iridis, forming minute cu}>like be dies, 

 on dead leaves of grass. It is allied to 

 Excipida, but differs in its concatenate spores 

 being connected by a slender thread, which 

 frequently breaks off with them ; spores 

 very gelatinous. 



BiBL. Berk, and Br., Ann. N. H. 2 ser. 

 V. 457 ; Cooke, Hamlb. 459. 



MYXOT'RICHUM, Kze.— A. genus_ of 

 Dematiei (H\^homycetous Fungi), growing 

 on rotten wood, paper, &c. Three British 

 species : M. ccesitim, Fr. ; 31. chartarum, 

 Kze. ; and M. dejlexum, Berk. They form 

 little tufts or downy balls, sending off 

 radiatius: branched filaments. The spores 

 are described as occm-riug collected in 

 masses about the base of the threads. 



BiBL. Berk. Br. Fl. ii. pt. 2. 335 ; Ann. 

 N. H. i. 2G0, pi. 8. fig. 9 ; Fries, Sum. Vey. 

 502 ; Syst. Mye. iii. 348 ; Church, Ann. 

 N. H. 1862. 



MY'ZUS,Passerini. — Agenusof Aphidfe. 

 Four species ; on the cheiTy-tree, peach 

 and nectarine, red-currant and gooseberry. 

 (Buckton, Ajihides, i. 173.) 



N. 



NACCA'RIA,Endl.— A genus of Ciypto- 

 nemiacese (Plorideous Algae), containing one 

 rare British species, N. Wiijghii (Pi. 4. 

 fig. 18), usually thrown up from deep water. 

 Its rose-coloiu-ed frond is 6 to 12" high, and 

 consists of a branched filiform expansion, 

 the central axis being about as thick as a 

 crow-quill, the branchlets quadrifarif)usly 

 alternate and clothed with ranmles about 

 1-12" lung. The cells of the main axis and 

 branches of the frond are large and empty 

 in the centre, small and closely packed at 



[ the circumference ; the raniulea are com- 

 posed of jointed dichotomous filaments 

 having a whorled arrangement, surrounded 

 bj' gelatinous matter. The .spores arebi)rne 

 on branches of the filaments of the ra- 

 mules, the fertile ramules being swollen in 

 the middle. 



BiBL. ll^Y\ey,Mar. Alg. 152, pi. 201); 

 Ph/c. Br. pi. 38; Greville, Ahj. Br. pi. IG. 

 NAIDI'NA.— A family of Setigera (An- 

 nulata). 



Char. Worm-like, annulate or segmented, 

 without suckers or soft leg-like appendages ; 

 segments furnished with partially retractile 

 bristles or seta3, excepting the first three or 

 four ; head distinct from the body. 



Freshwater animals, living among aquatic 

 plants, or burrowing iu mud. Sexes distinct; 

 propagation by ova and spontaneous trans- 

 verse division. The bristles are moved by 

 muscles, and answer the purpose of legs ; 

 they are situated on the upper or under 

 surface of the body, mostly in rows. 



The Naidina are remarkable for the sin- 

 gular process of non-sexual multiplication 

 which they present before attaining sexu d 

 maturity. A bud is thrown out between 

 two rings near the middle of the boJy, and 

 is developed into a fresh individual ; more- 

 over the parent body separates at this point, 

 and becomes two individuals ; and prior to 

 the detachment of the bud, others are 

 formed from the same segment. 



Nais, Miill. Four anterior segments 

 without upper bristles. 



N. Scotica. Cylindrical, ends obtuse, the 

 anterior smooth and cylindrical, the portion 

 behind it with a double row of thin tufts of 

 prickles, shorter than the diameter of the 

 body; mouth and anus terminal; no pro- 

 boscis; length 1". 



N. serpentina. Cylindrical ; head snake- 

 like, with a produced lower lip ; eyes two ; 

 upper bristles subulate, lower forked or 

 hooked; length about Ih,"  The lower 

 bristles with a globular swelling below the 

 middle ; segments SO-OO ; head with 4 dark 

 transverse band?. 



N. prohoscidca. Cylindrical, flattened iu 

 front ; first four segments divided by a 

 stricture from the body, the first or head 

 being prolonged into 'a filiform proboscis ; 

 two eyes; upper bristles simple, lower 

 forked ; length 1-2"; on the roots of aquatic 

 plants. 



Cliatogaster, Baer. All the segraents 

 without upper bristles. 



C. vennicidaris. Truncate in froi.t ; no 



2 H 2 



