KONGL. SV. VET. AKADEMIENS HANDLINGjAK. BAND 25. X:0 5. 151 



Gen. 27. Leptozosma, TVrxer. 



(On Desm., J. K. Micr. Soc. p. 934. t. XVI, f. 2) 



Nothing nearer to this than D. graciliceps, supra, has been observerl in India. 



The Rev. F. Wolle, in Torrey Bull, p. 58, 1886, did me the honour of criti- 

 cizing the form I deseribed 1. c. attrifouting it to Desmidium, (Didymoprium f) quadra- 

 tum Nordst., (Norges Desm. p. 49, f. 24) nearly as figured in t. XLIX, Desm. U. S. 

 A. The tig. No. 5 is not quädratum but graciliceps var. constrictum, Nordst.; this 

 however does not invalidate the fact that Mr. Wolle has considered a thick-walled 

 cell as a young Desmid-form! Lagerheim (Krit. Bemerk. Desm. p. 536, 1887) did not 

 fail to observe this. Xordstedt (Alg. N. Z. p. 25) considers that it »looks as a 

 Didymoprium (graciliceps or an allied form) viewed from the side». This I frankly 

 grant, but what the plant really is I know not! 



Gen. 28. Gymnozyga, Ehrb. 



(Berl. Monatsbér. p. 212. 1840, sec. Jacobs.; Kitz. Phtc. Germ. p. 140, nota! 1845; Bambusina, Kbtz. I. c. 

 p. 140; Didymoprium, Ralfs ex. p. ; Desmidium, Ralfs et Bréb. ex. p.: Hyalotheea, Bréb. ex. p.). 



1. Gym. moniliformis, Ehrb. (1. c; Jacobs. Desm. Danmk. p. 213, 1875; Desmidium bam- 

 businum, Bréb. in Chev. Micr. p. 271, nomen solum! 1839; Menegh. Synops. p. 204 

 (sp. ined.! sine descript.) 1840; Bambusina Brebissimii, Kutz., 1. c. p. 140, 1845; Sp. 

 Alg. p. 188, 1849; Bréb. Liste, p. 119, 1856; Desmidium Borreri, Ralfs Annals v. 

 XI, p. 375, t. VIII, f. 4, 1843; Hassall, Br. Fr. Alg., p. 343, t. 83, f. 9, 1845; 

 Hyalotheea bambusina, Bréb. in litt. ad Ralfs, 1846; Didymoprium Borreri, Ralfs 

 Annals v. XVI, p. 10, 1845). 



Long. 25—29, lat. 20—23 «. 



Northern India, J. S. ; Khasia, ex Utricularia sp., G. vox L. 



These cells are a little longer and narrower than the corresponding English form. 



Neither this genus nor Didymopriun} is represented in either Wallich's Mscr. 

 or bis gatherings from Bengal. 



Dr. Nordstedt, De Alg. et Char., No. 3, Nov. sp. Desm. Brås. 1889, divides this 

 genus into the following sections (sub-genera): 



A. Eugymnozyga. Cellulöe non armatae. 

 Typ. sp. G. moniliformis. 



B. Hoplozyga. ('elluhe aculeis armatte. 



Typ. sp. G. armata. Löfgr. et Nordst. 1. c. 



Gen. 29. Hyalotheea, Kutz. 



(Ehrf.nberg, nomen solum, desor. invalida! 1840; Kutz. Phyc. Germ. p. 140! 1845; sec. Wittr. Gotl. Sötv. 

 p. 47, 1872; Mixotcenium pro p.. Pelponte Des. Sub. Alp. p. 50, 1873). 



1. H. dissiliens (Smith) Bréb. (in Ralfs Br. Desm. p. 51, t. I, f. 1, 1848; in litt. ad 

 Ralfs 1846; Conferva dissiliens, Smith. Kngl. Bot. t. 2464. 1812; Desmidium muco- 



