230 Rhodora [December 



ing the reddish tint; Stigonema mitmtum (Ag.) Hass., z^". hortnoides 

 (Kiilz.) Born. & Flah., and Scytonema ocellaium (Dilhv.) Thuret. Sti- 

 gonema hortnoides occurred also in the gelatine, but not the other three 

 species just named ; and besides the Sfigonema, there were Aphano- 

 thece microscopica Nag., Flecionevia Nostocoriim liornet, Calothrix fusca 

 (Kutz.) Born. & Flah., Gloeocystis rupestris (Lyng.) Rab., G. ves- 

 iculosa Niig., and Mesofaenium Braunii DeBy. 



Before the mouth of the Flume proper, the stream flows rapidly over 

 a smooth, sloping rock, in the form of a thin sheet rather than a 

 stream in the ordinary sense. All through this sheet were scattered 

 tufts of a bright green filamentous alga which, on subsequent examina- 

 tion, seemed to be a species of Zygnema, with filaments 25-28 /x 

 diameter. No fruit being found, specific determination was out of 

 the question. Zygnemas are found in ponds and still waters gener- 

 ally, often forming large loose masses near the bottom where the 

 water is not very deep. The present habitat is certainly an unusual 

 one, and the smooth, unbranched filaments would seem little suited 

 to holding on to the smootii rock. 



As an adaptation there had been developed short rhizoidal pro- 

 jections, much in 'the same way as \\\& forma polyrhizum of Rhizoclo- 

 nium riparium (Roth) Harv. attaches itself to surf beaten rocks, 

 while \.Vq: forma implexutn, with perfectly simple filaments, is at home 

 in quiet bays, lagoons and ditches. It is curious to note that another 

 marine Rhizoclonium of our coast, R. tortuosum Kiitz., though with- 

 out rhizoids, resists being swept away by the waves, by means of its 

 densely crisped and twisted fronds, which entangle it with any algae 

 with which it may come in contact. 



Beside the species mentioned, there were found on the walls of the 

 Flume, the thin black sheets of Schizothrix Muelleri Nag. and in 

 quieter parts of the stream, Fhortnidiiim Retzii (Ag.) Gomont ; on 

 rocks just outside the Flume, Stigonema mamillosum Ag. 



The only reference heretofore to the algae of this locality that the 

 writer has been able to find, is by Prof. Farlow in Appalachia, Vol. 

 Ill, p. 232, 1884; the conditions of his visit were unfavorable, and 

 he reports only five species; Synechococcus aeruginosus Nag., Nostoc 

 rupestre Kiitz., N. muscorum Ag., Stigonema ocellatum (Dill w.) Thuret 

 and Trentepohlia aurea (L.) Mart. It is interesting to note that 

 none of these were observed at the present visit. This would seem 

 to imply either that there was more variety at different places along 



