cocco^:ema. 



[ 188 ] 



COCOA. 



elliptical, strife longitudinal, faiut ; length 

 1-1200 to 1-700" ; aquatic. 



C. flacentula. Frustules tiat ; valves el- 

 liptical ; striae longitudinal, faint ; length 

 1-760" ; fresh water, common. 



C. scutellum (PI. 16. fig. 16). Frustules 

 dorsally convex ; valves ovato-elliptical, 

 striae transverse or slightly curved ; length 

 1-700" ; marine. /3. Nodule dilated into a 

 stauros. 



C. Thwaifesii (^Achnanthidimn Jtexettum, 

 Bre'hiss., Kiitz.). Ends of valves slightly 

 produced ; fresh water, length 1-900". 



C. Grevillii. Oval, with transverse cana- 

 licidi ; marine. 



C. diaplmna. Elliptical, diaphanous ; 

 marine. 



Kabenhorst describes 37 European spe- 

 cies, with numerous varieties ; and enu- 

 merates 37 foreign species (with the re- 

 ferences). 



BiBL. Ehrenb. Infm. ; Kiitzing, Bacill., 

 and Sp. Aly. oO ; Smith, Brit. Dial. i. 21 5 

 Rabenhorst, Flor. AUj. i. 98 ; Greville, 

 Micr. Tr. 1804, 9, I860, 33, 1866, 126. 



COCCONE'MA, Ehr.— A genus of Dia- 

 tomaceae. 



Char. Frustules stipitate, navicular, some- 

 what arched (side view) ; valves with a 

 submedian line, with central and terminal 

 nodules ( = stipitate Cymbellce). Fresh 

 water. 



Valves transversely striated, the striae 

 being resolvable into dots. 



7 European species (Rab.). 



C. lanceoJatum (PI. 16. figs. 19 & 20). 

 Front view of frustules lanceolate, truncate 

 at the ends ; valves semilanceolate, very 

 sUghtly inflated at the centre of the concave 

 margin ; length 1-150", Common. Stipes 

 dichotomous, jointed. 



C. cymhiforme. Scarcely distinct from 

 the last (Sm.) ; stipules fihform, obsolete, 

 interwoven into a gelatinous mass ; length 

 1-330". 



C. cishtla. Front view elliptic-oblong, 

 obtuse ; valves inflated on concave margin ; 

 stipes elongate, filiform, simple or subrace- 

 mose ; length l-4o0" ; common. 



C. parvum (Sm.). Several other foreign 

 species. 



BiBL. Ehr. Inf. ; Smith, Br. Dmf. i. 75 ; 

 Kiitz. Bacill., and Sp. Ah/. 59. 



COCCOSPILE'RA, Perty.— An obscure 

 genus of Infusoria (Algae ?), consisting of 

 veiy minute spherical granules, with a black, 

 brown, or red nucleus, aggregated into ir- 

 regular revolving lumps, 1-400" in diuni. ; 



they exhibit slow motion. Tn turf-pits 

 &c. 

 BiBL. Pertv, Kleinst. Lehens. 1852, 104. 

 COCCOSPHERES.— The name given 

 by WalHch to minute lumps of colourless 

 protoplasm, found in deep-sea ooze, and 

 floating in the tropics. He describes them 

 as spherical or multilobed, from 1-5000 to 

 1-830" in size, imitating in shape Orbulina, 

 Nudosaria, Texiilaria, Rotalia, and Globi- 

 c/erina, and coated with numerous oval 

 Coccoliths (PI. 23. fig. 56 o). 



From the Atlantic ooze, also, Huxley 

 describes minute granular colourless sarcodic 

 bodies as Coccospheres, 1-4500 to 1-1700" 

 in diameter, some having Coccoliths on or 

 in them ; and he distinguishes (1) the com- 

 pact, hoUow, flattened sphaeroids with an 

 envelope, and (2) loose (1-4500 to 1-760"). 

 The corpuscles are free, touching or over- 

 lapping, 1-11000 to 1-4500" in breadth, 

 sometimesmingied with Coccoliths(l-11000 

 to 1-1600"). 



BiBL. That of Coccoliths, and WalUch, 

 Ann. A^. H. 1877, xix. 342 (figs.). 



COCCUDI'NA, Duj.— A genus of Infu- 

 soria, of the family Ploesconina. 



Char. Body oval, depressed or almost 

 discoid, often shghtly sinuous at the luargin; 

 convex, furrowed or granular and glabrous 

 above : concave beneath, and furnislied with 

 vibratile cilia and cirri or corniculate ap- 

 pendages, ser^ ing as legs ; no mouth. 



The species pf this genus known to 

 Ehrenberg are arranged among his Oxy- 

 trichina and Euplota. 



C. costata (Pl_. 50. fig. 3). Body obliquely 

 narrowed and sinuous in front, convex and 

 furrowed above, or with from five to six 

 very pi'ojecting tubercular ribs ; appendages 

 grouped at the two ends ; the anterior more 

 slender and vibratile ; length 1-950" ; in 

 marsh-water. 



Three other species. Dujardin remarks 

 that Ehrenberg's genus Aspidisca belongs 

 here. 



BiBL. Dujardin, Infns. 445 5 Claparede 

 and Lachmaun, Inftis. 188. 



COCKCHAFER. See Meloloxtua. 

 COCK-ROACH, or house black-beetle. 

 See Blatta. 



COCOA. — This substance consists of the 

 seeds of Theobronia Cacao (Ternstra?mia- 

 cex), and is largely used in a manufactured 

 form under this name ; and, mixed with 

 sugar and other ingredients, it forms choco- 

 late. The various powders and pastes thus 



very extensively 



designated are often 



