88 W. B. TURNER, FRESH-WATEK ALGJE OF KAST INDIA. 



Sub-section 1». Lateral margins distinctly lobate. 



Sub-genus C. Amblyastmiii (ä/ufiZvg, obtusus; etc). 



Lobes normally obsuse, not radiately arraiiged* 

 Typ. sp. E. oblongum, multilobatum. 

 D. Actinastrnm (dxrip, radius; etc). 

 Lobes sub-radiate. 

 Typ. sp. E. Nordstedtianum, clavatum. 

 Section II. Ewosmium, Nag. (Gått. einz. Alg-, p. 120) extend. 



Lobus polaris (vel apex) integer, non ineisnram singnlam ferens. 

 Sub-section a. Apex plain, crenate, or eräarginate; frond lobate or sublobate. 

 Typ. sp. E. commissurale, clepsydra, nobile. 

 » h. Apex not emarginate ; frond distinctly lobate (Eucosmium sensu strict.). 



Typ. sp. E. verrucosum, gemraatum, pectinatum; Nag. 1. c. 



Gen. 17. Micrasterias, Agdh. 



(Ag. in Flora 1827. p. f>42, fide WlTTR. Skand. Desm. p. 8; Ralfs Br. Desm. p. 68; Annals N. H. vol. XIV, 



]). 259; Menegh. Synopsis, p. '214). 



1. M. oscitans, Ralfs (in Jenner, Fl. Tunbr. Wells, ]>. 198, 1845; Holocystis oscitans, 

 Hassall Br. Fr. Alg. p. 386, t, XC, f. 4, 1845), fornue: 



a. typica. Ralfs Br. Desm. t, X, f. 2; Cooke in Grevillea, p. 90, t. 141, f. 2 f , 1881. 

 ii. intermedia, Nob. Cooke 1. c. f. 2 c, e. 



y. mucronata {Tetrachastrum mucronatum, Dixon, Dub. N. H. Rev. t. I, f. 5 — 8, 1859; 

 M. oscitans forma, Cooke, 1. c. f. a, d. 



a (Tet. oscitans, Dixon 1. <•. Long. 115, lat. 94 fi. 



/y. Long. 110, lat. 91 ,//. y. Long. 104—119, lat. 81-96 /ti. 



Sikhim; Bengal? 



Concerning this species it is not a little stränge that the tvpical form, figured 

 and described by Ralfs, is in England and elsewhere much more uncoraraon than the 

 other forms of this plant. 



2. M. laticeps, Nohdst. (Desm. Brås. p. 220, t. II, f. 14, 1869; Micr. incisa, Bailey, Micr. 

 Obs. t. I, f. 13, 1850; Tetrachastrum Americanum Archer in P. Inf. p. 725, 1861), 

 forma minor, Nordst. 1. c. 



Long. 118—129, lat, 138—151 //, lat. lob. pol. circ. 120 ,//. 



Bengal? Central India. 



I note that Nordstedt 1. c puts a query? as to Bailey's dimensions. The fignre 

 given by that author is certainlv M. laticeps; the dimensions are probably incorrect, 

 as my measure of Baileys lig. only gives long. 70, lat, 91 fi. 



3. M. pinnatifida, (Kutz.) Ralfs (Br. Desm. p. 77, t. X, f. 3; Euastrum pifinatijidum, 

 Ktz. Phyc, Germ. p. 134: Euastrum biftdum, Focke Phys. Stud. p. 64, t. I, f. 12; 

 t, II, f. 22; Tetrachastrum pinnatijidum, Archer, Prit. Inf. 1861), fornne: 



u. typica. Long. 50—57, lat. 60—66, lat. isth. 11, lat. lob. pol. 40, crass. 14— 15 .«. 

 T. V, fig. 3 a, e. (Wallicii Mscr. No. 87, 89, 1855; Beng. Desm. p. 275, t. XIII, 

 f. 1, 2, 3.) 



