CERVmiA. 



[ 155 ] 



CH.ETOGLENA. 



tornal coat of connpctive tissue, with scat- 

 tered, somewhat spindle-shaped nuclei, and 

 very tine nuclear fibres ; a layer of Hmooth, 

 longitudinal, ninscnhir fibres, consisting of 

 sliort fibre-cells with elongated nuclei; and 

 an inner single layer of epitlielium, com- 

 posed of polygonal cells, from 1-1800 to 

 1-1100" in diameter, with roundish nuclei. 

 These cells contain round or irregularly- 

 shaped 3'ellowish-brown granules, of very 

 various sizes, as also globules of oil. The 

 duct has a coat of connective tissue, and an 

 epithelial coat, consisting of several layers 

 of small nucleated cells, not containing fat 

 or pigment granules. 



UERVINTA, Noi-man. — A genus of 

 marine Copepodous Entomostraca. 

 C. Bradyi. Oban. 



BiBL. Bradv, Copepoda (Hay Soc), i. 85. 

 CESTODISCUS, Grev.— Fi'ustules disk- 

 shaped, cii'cular or oval ; valves with radia- 

 ting granules, and a submarginal circle of ob- 

 tuse processes unconnected by special radia- 

 ting lines of dots with the centre. 4 species. 

 BiBL. Greville, Mic. Trans. 1865, 48 j 

 18U6, 123. 



CE'TER ACH, Willd.— A genus of Ferns, 

 usually arranged with the Asplenie^, 

 although there is only a rudimentary iudu- 

 sium, the place of this being supplied by 

 scales. C. ajficiiiamm (Asjjlenium Cefe- 

 rach), the native species, occurs chiefly in 

 limestone districts. 



OETOCHILUS.— A genus of Entomos- 

 traca (Crustacea), belonging to the order 

 Copepopa, and famil)' Cetochilida3. 



l)istingiushed by the two small styliform 

 appendages to the head ; the two-branched 

 inferior antenn.ie, the branches nearly equal; 

 the unbranched jaw-feet; the six-jointed 

 thorax, and four-jointed abdomen; and the 

 last pair of legs being formed like the rest. 

 Marine. C.septentrionalis-^ bright red; forms 

 part of the food of the whale and various 

 fishes; length 1-10", 



Bldl. Baird, i?/-/;;. ^«i5o»2os. p. 2.3-3 ; Grob- 

 ben, Clam's Arh. 1880, 243, iii. {Jn. Mic. 

 &0C. 18.S1, i. 734). 



CETRA'BIA, Ach.— A genus of Lichens : 

 tribe Cetrarit i. 



C/tar. Thallus bright brown, rigid, erect, 

 or ascending, divided into laciniae, with 

 shining cortical layer. Apothecia dull or 

 bright brown. Spermatia cylindrical. 



3 British sp. : C. islandiva, the well-known 

 Iceland Moss ; C.Delisei; and C.aeidcata. 



BicL. Nvlander, Sy)i. 298; Leighton, 

 Lichen-Flora, 1879, 91. 



CETRARIR'I. — A tribe of Lichens; 

 family Lichenacei. 



Char. Thallus compressed, fruticulose, or 

 membranously dilated ; apothecia marginal; 

 spores 8, small, colourless, simpl(3. 



Genera : Cetruria and Plafysnia. 



CEUTIIOS'PORA, Fr.— A genus of Me- 

 lancouiei (Stylosporous Fungi) closely re- 

 lated to Phoma, one common species of 

 which (G phacidioidcs) grows on holly- 

 leaves; another occurs on the Cherry-laurel 

 (C. Lauri). It is probable that these are 

 only forms belonging to some Ascomycetous 



genus. 



C. phacidioides, Grev. 3-5 cells in the 

 stroma, splitting into 3-5 plain short teeth. 



C. Lauri, Sow, Unilocular, splitting into 

 3-4 acute teeth. 



BiBL. Berk. Hook. Br. Fl. ii. pt. 2. p. 283; 

 Grev. Crypt. Fl. pis. 253, 254. 



CILETO'CEROS,Ehr. 



-A genus of Dia- 



tomaceae. 



CJtar. Frustules concatenate ; valves equal, 

 subcylindrical, mth two processes, one on 

 each side, which, in the young state, are 

 very short and tubular, forming very long 

 horns as the frustules become older ; horns 

 subsequently converted into very long, thin 

 and interwoven siliceous filaments. Marine 

 and fossil. 



Somewhat allied to Biddidphia. Raben- 

 hoist admits 18 species. C. didymus (PI. 50. 

 fig. 47). Some British. 



BiBL. Ehrenb. Ber. d. Berl. A7c. 1844, 

 198; Kiitzing, Sp. Aly. 138; Brightwell, 

 3Iicr. Jn. vi. 155 ; Lauder, Mic. Tr. 1804, 

 75 ; Rabenhovst, FL Aly. i. 321. 



CH.ETOCOC'CUS, Ktz.— A doubtful 

 genus of Algse. 



Char. Filaments rigid, short, spiniform, 

 arising from a cellular substratum. 



C. violacevs, radiate, green, becoming 

 violet on diying, on Hhizoclonium ; C. hyuli- 

 iius, on Cladfijuhora. 



BiBL. Rabenhorst, Flor. Aly. ii. 199. 



CIIyETODIS'CUS, Grev.— A genus of 

 Diatomacepe. 



Char. Frustules disk-shaped; valves cir- 

 cular or oval, with radiating dots and a 

 submarginal circle of obtuse processes un- 

 connected by means of special radiating 

 lines of dots with the centre. 



4 speciee. 



BiBL. Greville, Mic. Tr. 1865, p. 48; 

 1806, p. 123. 



CILETOGLE'NA, Ehr.— A genus of In- 

 fusoria, of the family Peridiujea. 



Char. Carapace hispid, or studded with 



