CORPUSCULA. 



211 ] 



COSCINODISCUS. 



exhibiting the concentric rings, sometimes 

 forming cylindricttl, ramified, or reticular 

 fibres. Tliey are met \vitli in the choroid 

 plexuses, the pineal gland, the arachnoid 

 membrane, and sometimes in the walls of 

 the ventricles. These consist of an organic 

 (proteine) skeleton, containing carbonate 

 and phosphate of lime. When treated with 

 acids, the latter are dissolved, the former 

 being left and retaining the original form of 

 the concretions. 



BiBL. Purkinje, Midlers Archiv, 1836 & 

 1845 ; KoUiker, Mihr. An. ii. ; Virchow, 

 Archiv path. An. 135, 268, 416, and Ann. 

 N. Hist. xii. 481 ; Green, Pathology, 1871, 

 71 ; Frey, Histol. ; Eindfleisch, Path. 1878, 

 35. 



CORPUS'CTJLA, of the Coniferfe. See 



GVMXOSPEEMIA. 



CORROSIVE SUBLIMATE, the bichlo- 

 ride of Mercury. — A saturated solution of 

 this salt is very useful in rendering very 

 transparent bodies consisting of proteine- 

 compounds more opaque and distinct, as 

 the bodies and cilia of Infusoria &c. 



CORYC.E'US, Dana.— A genus of Cope- 

 poda (Entomostraca). 



C. anglicits. Marine. 



BiBL. Bradv, Copepoda {Ray Soc), iii. 

 32. "^ 



CORY'CTA, Duj. = Amosba bilimbosa, 

 Auerbach (Duj. Ann. d. Sc. N. 1852, p. 41). 



CORYMOR'PHA, Sars.— A genus of 

 marine Hydroid Polypi, family Tubulariida^. 



Bi3L. Hincks, Brit. Zooph. p. 125. 



CORYNACTIS, Allman.— A genus of 

 Anthozoa (Zoophytes). 



1 species : C. viridis. 



EiBL. Gosse, Actinologia Britannica (the 

 latest work on Sea- Anemones). 



CORYiSTE, Gfertn. — A genus of marine 

 Hydroid Polypi, family Corynidae. 



'BiBL. Hincks, BrU. Zooph. p. 37. 



C0RYN'EU31, Kunze.— A genus of Me- 

 lanconiei (Stylosporous Fungi), consisting 

 of pai'asitic plants growing upon dead twigs, 

 biu'sting out as convex solid pustules from 

 beneath the epidermis. A vertical section 

 of half of one of these pustules is shown 

 in fig. 144 ; the cellular stroma is covered 

 by stalked multiseptate spores. Six forms 

 are recorded as British. That figured, 

 C. disciforme, Kze., grows on dead twigs of 

 birch. 



Tulasne states this genus to consist of the 

 conidiiferous form of Melanconiei (Sphaeria- 

 cei). 



BiBL. Hook. Br. Ft. v. pt. 2. 355; 



Coryneum disciforme. 

 Vertical section of half 



a pustule. 

 Magnified. 200 diams. 



Berk. & Broome, Ann. Fig. 144. 



iV. H. 2 ser. v. 458; 

 Currey, Qii. Mic. Jn. v. 



127; Tulasne, Ann. Sc. 

 Nat. 4 ser. v. 110; 

 Corda, Icones Fang. 



CORYNO'PSIS; All- 

 man. — A genus of ma- 

 rine Hydroid Polypi, 

 family Hydractiniidje. 



C. Alderi. Durham. 



BiBL. Hincks, Brit. 

 Zooph. p. 34. 



COSCINODISCUS, 

 — Ehr. A genus of 

 Diatomaecce. 



Char. Frustrules free, single, disk-shaped; 

 valves circular, fiat, or sliglitly convex, ex- 

 hibiting a cellular or areolar appearance ; 

 no internal septa, nor lateral processes. 



The cellular appearance arises from the 

 existence of depressions, which are of 

 different sizes. The valves form beautiful 

 objects. 



Kiitzing enumerates forty-one species, 

 which are either marine or fossil. Smith 

 admits four British species. 



C. minor, E. Depressions irregular and 

 crowded (circular, Sm.) ; margin of valves 

 smooth ; freshwater and marine ; diam. 

 1-1200 to 1-500". 



C. radiattis, E. (PI. 51. fig. 1). Depres- 

 sions obscurely radiating, marginal ones 

 smallest ; margin of valves smooth ; marine 

 and fossil; diam. 1-550 to 1-180" (a, side 

 view ; h, front view). 



C. eccentricus, E. Depressions arranged 

 in curved lines, with the convexity towards 

 the centre ; marine and fossil; diam. 1-400 

 to 1-200". 



C. pyxidicula, Kg. (PyTidicuIa and Cras- 

 pedodiscus coscinodiscns, E.) (PI. 18. fig. 21). 

 Margin tumid, elegantly cellular, central 

 areola veiy fine, diminishing towards the 

 centre ; no umbilical star ; marginal cells 

 hexagonal, larger ; diam. 1-400". Fossil. 

 Virginia. 



C. craspedodiscus, K. = Craspedodiscus ele- 

 gans, E. (PI. 25. figs. 7, 8). Margin of 

 valves tumid, elegantly sculptured, central 

 markings radiating ; an umbilical star 

 formed of 5 to 6 .oblong larger cells ? ; 

 diam. 1-120". Fossil. Bermuda. 



C. oculus iridis. Areolae hexagonal, with 

 central " eve-spots." 



BiBL. Ehr. Ahhandl. Berl. Ak. 1838 and 

 1839; id, Ber. Berl. Akad. 1840 et seq.; 

 Kiitzing, Bacill. and Sp. Alg. ; Smith, 



p2 



