64 W. B. TURNER, FRESH-WATEK ALGJE OF EAST INDIA. 



Tliis seems nearest to C. laciniatum, No. 43, from which it differs in the sides 

 being sub-rotund or somewhat acute, and in the granules being scattered, not con- 

 centrically arranged. 

 SO. C. paradoxum, n. sp. C. sub-magnum, quarta parte longius quam latins, rotundatum; 

 semicellulae late ovales, lateribus rotundatse; membrana juxta isthmuni laevi, in superi- 

 orem partem 9 — 10 ordinibus granulorum obliquiter, vel in heptuncem, dispositis. 

 Sinn aperto, interne rotundato, amplo, extrorsum rotundato. A vertice visum late ovale. 



Long. 80, lat. 60, lat. islh. 34, er. 44 /u. T. IX, f. 22. 



Near to C. insigne, supra, but in this form the granules are doser in apposition 

 than in No. 57, and, moreover, in each transverse series there are 15 — 17 large gra- 

 nules, while in the other there are only 8 — 10 in each row, also verticallv there are 

 the same number of rows in both. The semicells, in C. insigne, are more globular in 

 in front view than in this form. 



87. C. Norimbergense, Reinsch (Alg. Frank. p. 113, t. IX, f. 2) var. microscopicnm (C. 

 microscopieuni \Y. B. T. in litt.). Var. minutum, fere ut in f. typica, sed apicibus 

 panllo attenuatum. 



Long. 8, lat. 5.5, lat. isth. 2 /u. T. IX, f. 28. 



This little form does not vary greatly in size, and is frequent in British ga- 

 therings. 



forma? Long. 12, lat. 8, lat, isth. 2.5 /u. T. IX, f. 43. 



Probably related to this species. 



88. C. staurochondrum, Lemaike (Desm. Vosges. p. 20, t. I, f. 1) var. orientale. Forma 

 typica differt apicibus non prolongatis, utro(pie latere apicum dente brevi munita, 

 stauros' granulorum non centrale sed apicali, et apicem versus sine granula minora. 



Long. 26—40, lat. 22—34, lat, isth. 7—11 ,u. T. IX, f. 23. 

 C. gemmatum var. fi, Wallich Mscr. No. 129. 



89. C. proteiforme, n. sp. C. variabile, circ. 1 1 / 2 -plo longius quam latins, ovatum; semi- 

 cellulae ellipticFB; membrana glabra, pnnctata, vel minute granulata!, sinn aut lineari 

 aut valde aequale aperto, externe ampliato; isthino brevissiino, vel collo parvo simili 

 (usque ad l / 14 parte longius). A vertice visum ovale; a latere biglolmlatnin, snb- 

 profnnde constrictum) fide Wallich Mscr. No. 138). 



Long. 21—42, lat. 14—29, lat. isth. 6—8, crass. 16 ,« (G. C. \A'. 1. c). 



The form in which the isthmus is prolonged into a short neck Dr. Wallich 

 styles a var.; this might be var. /? Wallichii. It is to be noted that this lengthening 

 of the isthmus regularly occurs in certain Indian forms, in this and other genera. 



T. IX, f. 26. 



90. C. sexaiiffulare, Lund. (Desm. Suec. p. 35, t. II, f. 23) var. IJengalense. C. minus quam 

 f. Suecica; angulis lateralibus sub-acutis, dorsalibus fere obliteratis; sinn profundo, 

 isthmo contracto; a, latere et a vertice visum angustius quam f. typica. 



Long. 22—37, lat. 18—27, lat, isth. 5.5—8, crass. 13- -20 //. T. IX. f. 30. 



91. C. seqnale, n. s]>. C. sub-mediocre, 5-ta parte longius quam latins, obtuse sexangulare; 

 semicelluhe rotundo-triangulares, basi et apice rotundata 1 , medio panllo tumida?, lateri- 

 bus in superiore parte panllo incavatis; membrana glabra: sinn profundo, angustissimo, 



