1-10 W. B. TURXER, FRESH-WATER ALG^E OF EAST INDIA. 



to them by Mr. Roy, as therein I have scen cells of tfais Dcsmid — the specimens 

 were kindly sent to me by Dr. Nordstedt. As I do not consider this as Eiirexbergk 

 species I append further notes under Sphaerozosma No. 9. 





The genus Onychonema falls naturally under two sub-genera: 



A. Frionema (tiqvcöv, serra; VTq/na, rilum). 



Filaments serrate at the sides in front view. 

 Typ. sp. O. uneinatum, lawe. 



B. Colponema (xoÅncodrjg, sinuosus; &c). 



Filaments sinuate or inciso-sinuate in front view. 

 Typ. sp. O. Nordstedtianum. 



Gen. 22. Sphaerozosma, Corda. 



(Almanach de Carlsbad, p. 207, 1835; Odontella, ex parte, Ehrb. Infus., et Teasamrthrtt EttR. 1. c, 1838, 

 non Tessarthronia, Turp. 1828; Isthmia, Menegh. Synops. ex. p. p. 204, 1840, uon Agardh; Isthmosira Kutz. 

 Phyc. Gerrn. p. 14 0, ex. p., 1845; Desmidivm, ex. p. Bkéb. Alg. Fal. p. 65, 1835; et Ralfs in Annals. p. 

 253. 1842; 6'chistochilum, Ralfs in Jenner's Fl. Tnnbr. Wells, p. 192, 1845, fide Ralfs; Sphcerozosma (a) 



Rabh. Fl. Kur. Alg. III, p. 148, 1808). 



1. S. vertebratum (Bkéb.) Ralfs (Br. Desm. p. 65, t. VI, f. 1, 1848; Wallich Beng. 

 Desm. p. 192; 5. elegans Corda, 1. c. t. IV, f. 37, 1835, t. IV, f. 30, 1840; Hass. 

 Br. Fr. Alg. p. 348, t. 84, f. 1, 1845; syn. plur. in auct. ut supra). 



Var. Indien m ; n. v. F. sinu magno plus minus cuneato; semicellulis non appro- 

 ximatis, cum isthmo distincto. 



a. Forma semicellulis sub-ovalibus lateribus rotundatis. F. lata. 



Long. 15—17, lat, 24, lat. isth. 8, crass. 9—10 /u. T. XVII, f. 18 a cd; Wal- 

 lich Mscr. No. 63. 



b. Semicellulis late ellipticis lateribus acute rotundatis. F. sub-acuta. 



Long. 14, lat, 26, lat. isth. 6—7 //. Fig. 18 b. 



»The deviations from the typical form of S. vertebratuni which occur . . . abun- 

 dantly, altliough great as regards size, are not otherwise of suflicient consequence to 

 demand uotice in this place», G. C W. p. 192, 1. c. From this it seems evident that 

 certain other plants hcreafter mentioncd wcre considered by Dr. W. as forms of this 

 species, although they appear, as noted b)- him in his Mscr. of 1855, upon different 

 drawings. 



2. S. excavatiini, Ralfs (Br. Desm. p. 67, t. VI, f. 2, 1S48; Schistochilum excavatum, 

 Ralfs in Jenner Fl. Tunbr. Wells, ]). 192, 1845; Sphairozosma e.vcavata, Ralfs in 

 Annals v. XVI, p. 15. t. III, f. 8, 1845; Isthmosira excavata, Kutz. Spec. Alg. p. 

 189, 1849). 



a. typica, Ralfs f. 2, 1. c. Long. 9 — 10, lat, 10, lat, constr. 6 /u. (Fig. e.) 

 P. heve. Rabh. Fl. Fur. Alg. III, p. 149; Rabh. Alg. Eur. sub No. 1224 b. (Fig. d.) 

 Long. 16, lat, 14 — 15, lat, isth. 6 /u; Wallich Mscr. No. 60 (cuin parasitis epi- 

 phyticis!) »no granular protuberances on the joints, which are smooth», G. C. W. 

 /. granulata? Rabh. Fl. Eur. Alg. 1. c.; Alg. Eur. sub No. 1338; granulis sparsis! 



