COSCINOSPIRA. 



[ 212 ] 



COTTON. 



Brit. Diat. I ; Wallich, Qu. Mic. Jn. 1860, 

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

 25, 43 ; 1866, 3, 78. 



COSCINOSPI'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 Jones, Ann. N. H. ser. 3, v. 180. 



COSMARIUM, Corda. A genus of Des- 

 midiacese. 



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, different from the circulation in 

 Closterium. From some observations by 

 Mrs. Thomas, it appears that the spore-cell 

 divides into numerous individuals in ger- 

 mination. 



Rabenhorst describes 77 European species. 

 Among the most common British species 

 are : 



C. pyramidatum (PI. 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. bioculatum. 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 (PI. 14. fig. 20). Punctate, 

 deeplv constricted ; segments crenate at the 

 margin, depressed at the end; end view 

 elliptical ; spines of sporangium very short; 

 length 1-470". 



C. tetraophthalmumCPLU.&g.W). Deeply 

 constricted ; segments semicircular ; end 

 view elliptical ; rough with pearly granules, 

 which give a crenate appearance to the 

 margin ; length 1-230". 



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

 Rough with pearly granules, which are as 

 broad as long ; end view elliptic ; segments 

 semicircular or reniform ; length 1-560 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. cucurbita. Punctate, constriction slight, 

 ends rounded; transverse view circular; 

 length 1-580". 



Lob b describes an extraordinary species, 



C. radiatum, the surface being covered by 

 densely crowded hyaline filaments, like 

 those of Actinophrys, but closer. 



BIBL. Ralfs, Desmid. 91 & 212 ; Thomas, 

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

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

 1864, 178. 



COSMIODIS'CUS, Grev. A genus of 

 fossil Diatomacea9. 



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, Qu. Mic. Jn. 1866, 79. 



COSMOCLA'DIUM, Br^b. A genus of 

 Desmidiaceae (Palmellaceae, Rab.). 



Char. Cells rounded, compressed, deeply 

 constricted, attached to a branched stipes. 

 Reproduction by gonidia. 



C. jmlchellum (PI. 61. fig. 38), attached ; 

 in turfy pools. 



2 other species (unattached). 



BIBL. De Bre"bisson, Liste d. Desm. 133; 

 Rabenhorst, Fl. Alg. iii. 53. 



COTHURNIA, Ehr. A genus of Infu- 

 soria, of the family Vorticellina, subfamily 

 Ophrydina. 



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- 

 cetta. 



Dujardin unites this genus with Vagini- 

 cola. 



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

 much shorter than the hyaline carapace ; 

 body yellowish ; aquatic ; length of carapace 

 1-280". Found upon Cyclops quadricornis. 



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 Sertularice &c. 



Stein adds 3 species, C. Sieboldii, C. 

 astaci, and C. curva ; found upon Astacus 

 flumatilis (the Cray-fish), Cl. & L. de- 

 scribe 12 species, 4 new, 



BIBL. Ehr. Inf. 297; Duj. Inf. 564; 

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

 121 ; Kent, JTw/. 719 ; Hutton, Jn. Mtc. Soc. 

 1878, i. 49. 



COTTON. The hairs from the epidermis 

 of the seeds of various species of Gossypium 

 (Malvaceae, Dicotyledons). These hairs are 

 readily distinguished under the microscope 



