COSCrXOSPIRA. 



[ 212 ] 



COTTON. 



Brit. Biat. 1 ; Wallifli, Q>t. Mic. Jn. 1860, 

 38 ; Greville, Mic. Trans. 1864, 9 ; 1865, 

 25, 43 ; 1866, 3, 78. 



COSCIN OSPI'RA, Ehrenberg. — The 

 elongate subtype of Peneroplis, one of the 

 Foraminifera imperforata. It is a synonym 

 of Spirolina, Lamarck. 



BiBL. Ehrenberg, Tr. Berlin Ac. 1839 ; 

 Parker and Joues. An7i. N. H. ser. 3, v. 180. 



COSMAIIIUM, Corda.— A genus of Des- 

 midiaceae. 



Char. Cells single, constricted at the 

 middle ; segments as broad as or broader 

 than long, neither sinuated nor spinous. 



A peculiar swarming motion is observ- 

 able at times in the cell-contents of this 

 genus, difterent from the circulation in 

 Closteri^iin. From some observations by 

 Mrs. Thomas, it appears that the spore-ceU 

 divides into numerous individuals in ger- 

 mination. 



Rabenhorst describes 77 European species. 

 Among the most common British species 

 are : — 



C, pyramidatum (PL 14. fig. 18, 19 empty 

 cell). Oval, with depressed and truncate 

 ends, deeply constricted ; end view ellipti- 

 cal ; segments punctate, entire ; length 

 1-470 to 1-260". 



C. hioculatum. Smooth, depressed, con- 

 striction producing a gaping notch on each 

 side ; end view elliptical ; segments subel- 

 liptic, entire ; sporangium orbicular, spi- 

 nous ; length 1-1410"'. 



C. crenatum (Pl. 14. fig. 20). Punctate, 

 deeply constricted ; segments crenate at the 

 margin, depressed at the end; end view 

 elliptical ; spines of sporangium very short ; 

 length 1-470". 



C. tetraophthalmum('P\.\A.?i.^.'22). Deeply 

 constricted ; segments semicircular ; end 

 view elliptical ; rough with pearly granules, 

 which give a crenate appearance to the 

 margin ; length 1-2:30". 



C. manjaritifernm (PI. 14. fig. 21). 

 Rough with pearly granules, whicli are as 

 broad as long ; end view elliptic ; segments 

 semicircular or reniform ; length 1-500 to 

 1-300". 



C. ornatum. Segments twice as long 

 as broad, rough with granules giving a 

 dentate appearance to the margin ; end view 

 with a truncate projection on each side; 

 length 1-610". 



C. cucurhita. Punctate, constriction slight, 

 ends rounded ; transverse view circidar; 

 length 1-580". 



Lob b describes an extraordinary species, 



C. radiatnm, the surface being covered by 

 densely crowded hyaline filaments, like 

 those of Actinophrys, but closer. 



BiBL. IX&lis, Desmicl. dlk2\2; Thomas, 

 Mic. Tr. new ser. iii. 33 ; Lobb. Qu. Mic. Jn. 

 1866, 55 ; Archer, Qu. Mic. Jn. 1860, 235, 

 1864, 178. 



COSMIOBIS'CUS, Grev.— A genus of 

 fossil Diatomacese. 



Char. Frustules simple, disk-shaped ; 

 valves radiato-punctate or areolar, with 

 linear radiating spaces (no processes nor 

 internal septa). 3 species : in Monterey 

 and Barbadoes deposit. 



BiBL. Greville, Qn. Mic. Jn. 1866, 79. 



COSMOCLA'BIUM, Breb.— A genus of 

 Desmidiacete (Palmellacete, Rab.). 



Char. Cells rounded, compret^sed, deeply 

 constricted, attached to a branched stipes. 

 Reproduction by gonicUa. 



C. pulchdJum (PI. 51. fig. 38), attached ; 

 in turfy pools. 



2 other species (unattached). 



BiBL. De Brebisson, Lisfe d. Desm. 133; 

 Rabenhorst, Fl. Alq. iii. 53. 



COTHURNIA, Ehr.— A genus of Infu- 

 soria, of the family Vorticellina, subfamily 

 Ophrydiua. 



Char. Solitary ; carapace urceolate, 

 stalked, fixed by the posterior extremity. 



An anterior ring of^ cilia is present. The 

 body contracts suddenly, like that of Vorti- 

 cella. 



Dujardin unites this genus with Vagini- 

 cola. 



C. imberhis, E. (PI. 32. fig. 20). Stalk 

 much shorter than the hyaline carapace ; 

 body yellowish : aquatic ; length of carapace 

 1-280". Found upon Cyclops qiiadricvrnis. 



C. maritima, E. Stalk much shorter 

 than the carapace ; body whitish, hyaline ; 

 length of carapace 1-570". On Ceramium. 



C. havniensis, E. Stalk much longer 

 than the carapace ; body whitish; length of 

 carapace without the stalk 1-280", stalk 

 twice this length. On Scrtularice iSrc. 



Stein adds 3 species, C, Sieboldii, C. 

 astaci, and C. curva ; found upon Astacus 

 Jliiviatilis (the Cray-fish), CI. & L. de- 

 scribe 12 species, 4 new. 



BiBL. Ehr. Inf. 297; Duj. Inf. 564; 

 Stein, Infus. ; Clap. & Lachm. Infns. i. 

 121 ; Kciit, /«/. 719 ; Ilutton, Jn. Mic. Soc. 

 1878, i. 49. 



COTTON.— The hairs from the epidermis 

 of the seeds of various species of Gossypium 

 (Malvacepe, Dicotyledons). These hairs are 

 readily distinguished imder the microscope 



