170 F. KITTOX ON DIATOMAOEARUM D1LLWYNII. 



aureis, articulis diametro sub-brevioribus domum in glomerulus 



sub-ovatis moniliformes approximates mutatis. — PI. VI., f. 3. 



Among the leaves of water-weeds in the river Lea at Waltham- 

 stow. 



In March, 1602, 1 found a few detached filaments of the present 

 plant mixed with those of C. lineata among the Tremella-like 

 slime with which, as I have before mentioned, many of the plants 

 in the river Lea are covered. 



I have not discovered any filaments that appear to be at all 

 perfect, but they seem to be sufficiently so to prove that the plant 

 differs materially from every other British species. 



The filaments are cylindrical, of a brittle nature, and reddish, 

 yellowish, or yellowish-brown colour. The internal vesicles which 

 constitute the joints appear to be at first cylindrical, but at length 

 collapse into an oral, form, so as to (/ire to the filaments, when 

 highly magnified, some resemblance to a series of guineas (italics 

 mine. — F. K.) 



The length of their joints are generally somewhat less than 

 their diameter. 



(The slide from Dillwyn's collection marked C. nummuloides is 

 without locality or date, but the name is in the author's hand- 

 writing. The species is attached to a marine alga, upon which 

 were also growing Melosira Borreri, Grammatophora marina, and 

 Synedra ajfinis. The form figured and described in the " British 

 Conferva?" could not have been from the river Lea at Waltham- 

 stow, as all the above-named forms are marine. — F. K.J 



G. ochracea. — C. fills ramosissimus tenuissimus perfragilibus, 

 densissime compactis, gelatinam ochraceam, tarn en in floccos sece- 

 dentum constituentibus. 



In pools and ditches ; common. 



(This form was placed by Hassall " Freshwater Alga?," vol.i, p. 

 400, as Melosira ochracea and with Diatoms as synonymous with 

 Gallionella ferruginea. A careful examination of Dillwyn's speci- 

 men does not confirm this, and I am unable to distinguish anything 

 like a Diatom frustule. A fragment treated with nitric acid was 

 destroyed by its action. Dr. Kutzing (" Bacillarien," p. 5G) 

 says : — lt Ganz ausgeschlossen muss werden Gallionella ferruginea 

 Ehr. welche kein Diatomee sondern einc Confcrvcaest." Dr. Wer- 

 neck, in 1841, gave figures of G. ochracea and G. ferruginea, and 

 which represent two distinct species. His figure of a filament of 



