219 



Notes on Palmod^ctylon subramosum, and on a New British 



Species of Vaucheria. 



By M. C. Cooke, M.A., A.L.S. 



(Read October 25th, 1885.) 



Plate XIV. 



On page 25 of my recent work on British Fresh Water Algas I 

 have stated that " one or other of the many forms of Hydrurus 

 penicellatus has been called Palmodactylon subramosum, Nag." 



This form has recently been found in Britain, and a fragment 

 sent to me for verification by Mr Thomas Hebden, of Hainworth, 

 near Keighley. It was found during the month of July, but in 

 small quantity, and mixed with other species. The collector says : 

 " I have been repeatedly to the same place but so far have not been 

 able to procure another specimen." 



This form was described by Niigeli in his " Unicellular Alga3 " 

 (p. 70), under the name of Palmodactylon subramosum, and was 

 repeated under the same name in Rabenhorst's " Flora Europtea 

 Algarum " (p. 44), and Kirchner adopts it in his " Algen von 

 Schlesien" (p. 107). Nevertheless, we see no reason to modify our 

 original view, that it is only one of the many forms of Hydrurus. 

 Unfortunately the specimens found were so meagre as to be insuffi- 

 cient to furnish any conclusive evidence. 



On page 116 of the above work I have given a synopsis of the 

 known species of Vaucheria found in Europe, according to the 

 arrangement adopted by Professor Nordstedt. When that list was 

 made eight species were known to occur in Great Britain out of a 

 total of 19, all belonging to the first group of 11 species, leaving 

 group B, with six, and two uncertain species, unrepresented. 



Since then Professor Nordstedt has spent some time in this 

 country, rambling in many directions in search of Fresh Water 

 AlgEe, and he has succeeded in finding on the mud of the Thames, 

 at Kew, above the bridge, at low water, another Vaucheria, his 

 own species of Vaucheria spho?rospora which belongs to the B 

 group, section Piloboloidea?, numbered 15 in the above-named 

 synopsis. This, therefore, is an interesting addition to our Flora, 



