812 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



coplea comta, EM. pi. 38. 1 b. Asia, 

 Africa, &c. Front view tumid at the 

 sides. Altliough this species is said to 

 have a g-raniilated umbilicus, none of 

 Ehrenberg's figures exhibit this cha- 

 racter. 



C. dendrochisra (E.). — Disc smooth, 

 except a circlet of short rays. = Discoplea 

 dendrochmra, E. On trunks of trees, 

 Venezuela. Frustules small, tumid in 

 front view. Diam. of disc 1-1920"; cen- 

 tral circlet with about ten rays. Habit 

 of C. comta. 



C. atmospherica (E.). — Disc with a 

 central, rather turgid umbilicus, from 

 which radiate numerous striae. = Discoplea 

 atmospherica, EM. pi. 39. 1. f. 17. In 

 atmospheric dust. Diam. 1-1008". 



C. Sinensis (E.). — Disc with a central, 

 rather turgid, granular umbilicus, from 

 which radiate numerous striae ; the stride 

 separated from the umbilicus bv a border. 

 = Discoplea Sinensis, EM. pi. 39. l.f. 16. 

 Atmospheric dust. China, &c. Diam. 

 1-864". Kays much closer than in C. 

 aUnospherica, and smooth, not rough as 

 in that species. In front view linear, 

 with striated margins, (xv. 4.) 



C. Atlantica (E.). — Disc with a central, 

 somewhat granular umbilicus, from which 

 proceed numerous radiating lines. = Dis- 

 coplea Atlantica, EM. pi. 39. 3.^ f. 29. 

 Atmospheric dust. Atlantic. Smaller 

 than the last, and its umbilicus not cir- 

 cumscribed by a rim ; but we doubt 

 whether this and the two preceding spe- 

 cies are sufficiently distinct, (xv. 3.j 



C. Oregonica (il.). = Discoplea Oreqo- 

 nica, EM. pi. 37. 2. f. 3. Oregon. Eh- 

 renberg's figui-e represents a small disc 

 with a central punctated umbilicus, from 

 which proceed numerous rays. Front 

 view linear, with marginal striae. Does 

 this differ from C. Sinensis ? 



C. venusia (E.). — Disc with granulated 

 umbilicus and numerous smooth rays. = 

 Discoplea venusta, ERBA. 1852, p. 534. 

 Alive. . California. Akin to C. atmo- 

 spherica ; frustules with the stellate habit 

 of Actinocyclus. Ehrenberg observed 

 three specimens. In one the umbilicus 

 was nearly equal to a fourth part of the 

 diameter of the disc, and the entire sur- 

 face very nearly smooth ; in another the 

 surface was distinctly granulated, and 

 the umbilicus, having its margin oblite- 

 rated, was scarcely evident. 



C. Astresa (E., K.). — Disc with a large 

 punctated centre and deuselv-raved mar- 

 gin. KSA. p. 19. = a HotulaiKBA. 2. f. 4 ; 

 8BD. pi. 6. f 50 ? Kurdistan ; Ireland. 

 Diam. 1-636". It has the habit and size of 



Melosira varians, but is not concatenate. 

 C. Rotida is a marine species. 



C. Pei'uana (E., K.). — Disc with very 

 fine rays, reaching to the centre. = Dis- 

 coplea pertiana, EM. pi. 38 a. 14. f. 6. In 

 pumice from Arequipa and Santiago, 

 Peru. Resembles C. Astresa. Diam. 

 1-600". The thickness of the frustule 

 equals half its length. Although the rays 

 are described as reaching the centre, the 

 figures show an umbilical space. 



C. oligactis (E.). = Discoplea? oligactis, 

 EM. pi. 35 A. 9. f. 1. Ganges. Ehren- 

 berg's figure shows a smaU disc, with 

 striated rim and irregidar umbilical 

 space, from which proceed a few irregu- 

 lar rays. 



C. Grceca (E.). — Disc plane, inter- 

 ruptedly striated in a radiate manner. = 

 Discoplea Grceca, E. = Coscinodiscus Grce- 

 cus, KSA. p. 125 ; EM. pi. 6. 2. f. 1. Fossil 

 in Greece. Diam. 1-864". 



C. antiqua (S.). — Valves convex; striae 

 broad, not reaching the margin. Diam. 

 •0009" to -0013". SBD. i. p. 28, pi. 5. f. 

 42. Lough Mourne and Peterhead de- 

 posits, &c. 



C. picta (E., K.). — Disc plane, broadly 

 granulated in the middle, its margin 

 densely radiated ; rays very slender, ele- 

 gantly mixed with pairs of stouter ones. 

 KSA. p. 20. African coast. Disc some- 

 times large. 



C. Rota (E., K.). — Disc large, with 

 numerous (52) equal rays, not reaching 

 to the centre ; surface papillose ; papillae 

 unequal, smallest between the rays, 

 largest at the centve. = Discoplea Rota, 

 EM. pi. 35 A. 22. 1 6. Southern Ocean. 

 Diam. 1-192". This and the next species 

 are distinguished from the rest by having 

 papillae or granides in the intervals of 

 the ravs. 



C. Rotula (E., K.). — Resembles C. 

 Rota, but is smaller, its rays fewer in 

 number (20), and its papillae equal. = 

 Discojjlea Rotula, EM. pi. 35 a. 22. f. 7. 

 Southern Ocean. Diam. 1-696". As in 

 C. Rota, the rays extend from the margin 

 towards, but do not reach the centre. 



C. denticidata (E., K.). — Disc marked 

 with straight, parallel, granidated lines, 

 and its margin denticulate. KSA. p. 20. 

 Bermuda. Diam. 1-672". In the character 

 of its margin it resembles Melosira sul- 

 ccda, but in the arrangement of its gra- 

 nules it approaches Coscinodiscus lineatus. 



C. undidata (E.,K.). — Disc with radiat- 

 ing lines of very minute granules, and an 

 undulated margin. = Discoplea undidata, 

 EM. pi. 33. 18. £ 3. Bermuda. ]>iam. 

 1-576". Marginal fiexures about fifteen. 



