STRUCTURE AND SYSTEMATIC POSITION OF CHANTRANSIA. 209 
On the Structure and Systematic Position of ee 
a Description off New Species. By Gzorez Muprfay and 
Eruet S. Barton. 
[Read 5th June, 1890.] 
(Puates XXXVI. & XXXVII.) 
THE genus Chantransia has been, since its establishment, one of 
the most interesting among Algæ, not only on account of its re- 
markable position as one of the so-called primitive types of Flo- 
rideæ, but also from a supposed relationship ascribed to certain 
of its forms with Batrachospermum and Lemanea. The history 
of the genus is, in fact, an exceptionally stormy one ; its syste- 
matic position has been the subject of argument, the generic 
characters have been emended and its validity as a genus has been 
challen ged. Itis happily unnecessary for us to penetrate farther 
into the history of these changes than the Thuretian conception 
of the genus. This author writing (1863) in * Le Jolis, Algues 
Marines de Cherbourg,’ p. 104, says :— 
“ The genus Chantransia has not been kept to the limits assigned 
to it by De Candolle; since it contained species belonging to 
Lemanea, Batrachospermum, Cladophora, and Edogonium (Fl. Fr. 
li. p. 49 et seg.). Fries re-established it later (1825) on a better 
basis, taking for its types Conferva Hermanni and C. chalybeia of 
Roth. These two plants, living in freshwater, bear a strong re- 
semblance to certain minute marine species which form part of 
the Callithamnion of Lyngbye. Harvey long ago recognized this 
resemblance, which had compelled him in 1836 to re-unite the 
marine and freshwater species under the genus Trentepohlia 
(Mackay, Flor. Hibern.). More recently, however, this celebrated 
algologist has changed his opinion and replaced the marine species 
in Callithamnion. He has even described and figured for some 
of them veritable tetraspores (Phye. Brit. tabb. 313, 314). The 
existence of such organs would justify the position which he 
assigns to these plants if it were well demonstrated. But I think 
that there is some error here resulting from the study of dried 
specimens. At least I have never been able to find tetraspores, 
and I trust implicitly on this point to the excellent observations 
of M, Areschoug (Phyc. Scand. marin. p. 115), confirmed recently 
