KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 5. 135 



observation of Wallioh is very interesting as to the possible existence of »swarm cap- 

 sules\ éach with a membranous investinent. I have often seen the phenonienou 

 myself, but the granules always appeared to me to be free within the semicell. 



[Semic. cum parasita (endophyte?). T. XII, f. 12, after G. C. W. Mscr. No. 171. 

 Wallich says that when thus attacked the endochroine collapses as at a; »a number 

 of vibratile granules (b) of a brownish eolour being retained between it and the end 

 of the segment. From the other extremity of the endochrome-membrane arises a tube, 

 vvhich expands in diameter until it reaches the eell-wall, and it then contracts into 

 a, narrow neek (e), passes through the wall, and tinally again expands . . . and extends 

 outwards. Have observed this phenomenon in many species.» G. C. W. Might not 

 this be a formation cmalogous to that in Archers observation on Zoospores in Desm. 

 (X. H. Soe. 'Irans. Dul)l. t. I, f. 1 — 4, 1860)? My own opinion being that what Archer 

 saw were really the tubes of an Endophyte, and not due to a Desmidian effort to 

 produce zoospores! Probably something allied to Olpidiurn Al. Braun. Cfr Braun, 

 Uber Chytridium, &c, 1855; idem, Alg. I nieell. 1855; Cienkowsky, Kennt. de Mo- 

 naden, 1865; Cornu, Bull. Soc. Bot. de France, T. XIX. 1872; Sorokine, Ueb. Wasser- 

 pihe, Bot. Zeit. 1874; idem, Siphomycétes, Bull. S. Xat. de Kazan, 1S74; idem, Chy- 

 tridiacées, 1 <SS3 ; Keinsch, Ueb. Saprolegnien, Parasiten, t. XVII, f. 11 — 12, 1885; also 

 Boldt, Sibir. Chloroph. t. \ r , f. IS, in whieh A', antilopceum, with a similar pärasite, 

 is depieted; and Arciiei: in Dubl. Club. Proc. in Q. I. Mic. Sei. p. 199, 1869]. 



7. A. curvahis, n. sp. A mediocris, habitu A. convergenti eonsimilis, sed semieellulis sub- 

 cuneatis non ovalibus; aculeis longioribus et validioribus quam in specie comparata, 

 curvo-reeurvatis (non convergentibus) horizontaliter positis, et sinu latiore valde aperto, 

 differt. A vertiee visus elongato- vel compresso-ellipticus. Zygospora splnerica, hevi. 

 a. Forma typica. Long. 34 — 40, lat. s. acul. 34 — 40, c. acul. 51 — 60; lat. isth. 10 



—13, erass. 15—17, long. acul. 13—18 ,u. T. XI, f. 33, XII, f. 2 (also Wallich 

 Mscr. 173 A.). 



Zygospore diam. 29 /u, T. XII, f . 1 1 , after Wallich, No. 179. 

 1). Forma major. Major, semieellulis euneatis, cornubus longis crassis. 



Long. 44, lat. s. aeul. 42, c. ae. 84, lat. isth 12, crass. 19, long. acul. 22 ,u. 

 T. XI, f. 35; XII, f. S. 



Verv frequent in Wai.lkiis Bengal collection of 1855. 



[T. XII, f. 7, represents ordinary vegetative cell-division; f. 13 X 550 represents 

 a Desmidian curiosity. G. C. W. says, »the two new and smaller segments placed 

 exterual/f/ to the old ones.» I need not quote my friend further, as I think his view 

 is erroneons, my own idea being that two new and larger segments (in fäet »forma 

 major- !) were developing from t/ro old semicells of normal size — this theory may 

 possibly account for the appearanee of large forms, not at all different except in size. 

 T. XII, f. 15 X 550 represents »two recently separated fronds exhibiting the sustaining 

 and still uninterrupted cell-membrane» (mucous investinent). G. C. W. sub. Xo. 17S. 

 Mscr. These 3 tigures are after Wallich.] 



8. A. Indiens, n. sp. A. sub-magnus. s. ac. fere tam longus quam latus; semieellulis tri- 

 angularibus vel late euneatis, dorso paullo rotundatis vel leniter incurvatis, basi parum 



