86 



THE JOURNAL OF BOTANY 



54 fx ; lat. 30 /x ; lat. isthm. 9 /x. Hah. In small stream, Mosman, 

 N. Queensland. 



h. Forma cum undulo singulo in marginibus lateralibus supra 

 et juxta angulum inferiorem rotundatum ; long. 90 /x ; lat. 47 /x ; 

 lat. isthm. 13 /x. Hah. Backwater on Big Mosman Eiver, 

 N. Queensland. This form is closely allied to, and probably 

 identical with, var. pyxidattim Delp. 



The real characters of E. ansatum are apparently little under- 

 stood, in consequence of which this w^ell-known Desmid has been 

 described from tropical and subtropical countries under various 

 new names. The following recently described "species" can only 

 be regarded as forms of E. ansatum : — 



E. securiformiceps Borge in Arkiv f. Botan. utgifv. af K. Sv. 

 Vet.-Akad. Bd. 1, 1903, p. 112, t. 4, f. 29. 



E. rotundum Play fair in Proc. Linn. Soc. N. S. Wales, xxxii. 

 1907, p. 170, t. 5, f. 20. 



E. suhansatum Bernard, Prot. et Desmid. Java. Dep. de I'Agric. 

 Ind. Neerland. Batavia, 1908, p. 122, f. 199-201. 



E. tropicimi Bernard, op. cit. p. 123, f. 202, 203. 



MiCRASTERiAS MoBii (Borgc) W. & G. S. West in Journ. Linn. 

 Soc. Bot. xxxiii. 1897, p. 162; in Botanisk Tidsskrift, 1901, p. 170, 

 t. 3, f. 21. 



Fig. 4. — Micrasterias M'dbii (Borge) W. & G. S. West yq,y. javanica Gutw., 

 X 500. a, front view ; h, side view of another specimen ; note the difference in 

 the lobulation of the two semicells. Mosman, N. Queensland. 



Var. JAVANICA Gutw. in Bull, de I'Acad. Sci. Cracovie, Nov. 

 1902, p. 603, t. 40, f. 58. One of the principal features of this 

 variety, namely, the character of the central protuberance, is 

 entirely omitted from Gutwinski's description, and but feebly 

 indicated in his fig. 58 c. In typical Micrasterias Mohii the cen- 

 tral protuberance is rounded and scrobiculate ; in var. javanica it 

 still retains some of the scrobiculations, but in addition it possesses 

 a ring of rather large verrucse. The only essential features of 

 var. javanica are as follows : — 



