CH/ETOPSIS. 



[ 157 ] 



CHALAZA. 



Confervoid Algae, growing in sea or fresh 

 water, rarely terrestrial, invested with gela- 

 tine ; either tilii'orm, or (a number of tila- 

 ments being connected together) expanded 

 into gelatinous, branched, delinitely-foruied 

 or shapeless masses or fronds. Filaments 

 jointed, famished with bristle-like processes. 

 Fructification consisting of spores ; and four- 

 ciliated zoospores, formed out of the con- 

 tents of the articulations. 



Si/?702)sis of British Genera. 



Draparnaldia. Filaments free, gelati- 

 nous, the primary nearly colourless, bearing 

 tufts of coloured ramuli at the joint ; zoo- 

 spores formed singly in the joints of the 

 ramuli. 



Chcptophora. I'ilaments dichotomously 

 branched, aggregated into shapeless, in- 

 crusting or branched, gelatinous fronds, the 

 joints bearing bristle-like branches; zoo- 

 spores solitary in the articulations ; the 

 membranes of the filaments very fugacious. 



Coleochccte. Frond disk-shaped or ir- 

 regularly expanded, adherent to leaves &c. 

 of aquatic plants under water, formed of 

 jointed dichotomous filaments radiating 

 from a centre, more or less conjoined late- 

 rally; the joints producing from the back a 

 slender truncate open tube, from which a 

 long bristle is exserted. Fructification : 

 spores and zoospores formed in the joints. 



OcMochcBfe. Frond discoid, appressed ; 

 filaments cylindrical, radiating from a centre, 

 irregularly branched, consisting of a single 

 series of cells, each of which is commonly 

 prolonged above into an articulate bristle. 



Foreign genus. See Aphanoch-s;te, 

 Kiitz. 



BiBL. See the genera. 



CH.FTOP'SIS, Grev.— A gemis of Mu- 

 cedines (Hyphomycetous Fungi) charac- 

 terized by erect jointed threads, whorled 

 below, above simple and flagelliform, bear- 

 ing cylindrical spores from the tips of the 

 branclilets. One species only is known, C. 

 Wauchii. 



BiBL. Grev. Crypt. Fl. pi. 23G ; Berkeley, 

 Br. Fung. .35.3 ; Cooke, Handbook, 614. 



CH.ETOSPI'RA, Lachmann.— A genus 

 of Infusoria, of the family Bursarina. 



Char. Buccal spire supported on a nan-ow 

 band-like process, at the base of which is 

 the mouth. 



C. Miilleri. Shell lageniform, horny. On 

 torn leaves oiLemna trisulca. 



C. mucicola. Shell gelatinous. Among 

 Algae, fresh water. 



BiBL. Ann. N. 11. 1857, xix. pi. 9. figs. 6 

 and 7 ; Claparede and Lachmann, Inftts. 216 ; 

 Kent, Infus. 601. 



CH^TOSTllO'MA, Corda. See Volu- 



TELLA. 



CH^TOTYPH'LA, Ehr.— A genus of 

 Infusoria, of the family PeridinEea. 



Char. Carapace (siliceous P ) hispid or 

 covered with rigid hairs ; no transverse 

 furrow, no eye-spot. 



C. armata (PL .30. fig. 26 : a, side-view ; 

 h, posterior end view). Ovato-subglobose, 

 rounded at each end, hispid with short 

 setae, posteriorly a ring of dark prickles ; 

 length 1-0:20". 



C. aspera (PI. 30. fig. 26 c). Oblong, 

 rounded at each end, hispid with short setse ; 

 posterior prickles scattered without order ; 

 length 1-550". 



C. ? pyritce. Oblong cyliudiical, ends 

 rounded ; sette slender and elongate ; no 

 posterior prickles ; length 1-llOU", breadth 

 half the length. Fossil in flint. Ehreuberg 

 questions whether this is not a Xanthidium. 

 BiBL. Ehr. Infus. 250; Duj. Inf. 328. 

 CHAITOPH'ORUS, Koch.— a genus of 

 Aphidse. 



Char. Antennae hirsute, 7-jointed; upper 

 wings with a doubly forked cubitus ; lower 

 with two oblique veins; abdomen studded 

 with tubercles tufted with bristles : dimor- 

 phous. 



Several species ; occurring upon the wil- 

 low, poplar, birch, &c. 



BiBL. Buckton, Aphides {Hay Sac), ii. 

 120. 



CHA'LARA. — A genus of Mucedines 

 (Hyphomycetous Fungi) ; characterized by 

 the erect jointed threads, which at their 

 slender apices break up into cylindrical 

 spores. 



C. longipes has been found in this countiy. 

 BiBL. Sturm, D. Fl. 29, pi. 35 ; Saccardo, 

 Fasc. i. pis. 29-35. 



CHALA'ZA (in plants). — The teim ap- 

 plied to the base of the nucleus of ovules, 



Fis-. 116. 



Ch^ 



r_U-, 



Section of an anatropons ovule : /", fimiculns : r, 

 raphe; ch, chalaza; p, external coat of testa ; s, inter- 

 nal coat or tegnjen ; n, nucleus. 



where the substance of the former is con- 



