138 



BRITISH CHAKOPHYTA. 



var. erythrocarpa. 



Geoves & Bullock-Websteb. in Joum. Bot. LYII, p. 225 (1919). 



Oospore broadly ellipsoidal, c. 350-400 /a long, 300- 

 350 /x broad, reddish brown to dark red; outer mem- 

 brane yellow-red to red-brown, linearly granulate, with 

 smooth intervals frequently occurring between the 

 granular lines. 



DiSTREBUTioN. — Woles : Anglesea, Llyn Coron {J.E. 

 Griffith, 1887). 



Ireland : Leitrim, Lough Melvin (E. Lloyd Praeger, 

 1899) ; Donegal, W., Lough Magheradrumman (G. B. 

 B.-W., 1916). 



There appear to be several variations of this species tend- 

 ing towards T. nidifica. Professor Hy in his ' Characees de 

 Prance ' (p. 20) has the following note : " Forma littorea vert 

 sombre, a incrustation nulla ou faible, des eaux saumatres. 

 Poiute des feuilles a dernier article court et peu attenue. 

 Plante noircissant encore par la dessiccation et assez flexible en 

 herbier. Differe du vrai T. nidifica des mers du Nord, par 

 le nucleus de I'oocarpe plus petit, n'atteignant pas en moyenne 

 0'39 millimeti'es, a surface finement ponctuee et non vermi- 

 culee, presque lisse." 



On the other hand Braun in the ' Fragments ' (pp. 94, 95) 

 refers to a form of T. nidifica var. intermedia which approxi- 

 mates to T. glomerata. He writes: "Forma intermedia. Ireland. 

 Dr. Moore in herb. Hooker. Habitus N. nidificse balticse, 

 folia verticillorum fertilium eodem inodo incurva et obtusa. 

 Color nigrescens, Semina minora magis contorfca 10-gyrata, 

 unreif. 0-46-48 mm. lang, ohne Kronchen 0'43-44 mm. lang, 

 Kern hell gelbgriin 0'30-35 mm. lang." 



Both authors refer also to other intermediate forms, but 

 none of these are stated to possess the red fruit of T. nidifica 

 with the granulate membrane of T. glomerata, which are the 

 main characteristics of our variety, erythrocarpa. A fuller 

 investigation of the intermediate forms is very desirable. 



[T. hispanica Nordst. and T. giennensis Prosper are closely 

 allied to T. glomerata. The former, a Mediterranean species, is 

 dioecious, the latter, from the south of Spain, is described as 

 having the oogonia and antheridia on separate branches. In 

 both of them the antheridia are much larger than in the 

 British T. glomerata, being 700-800 /x in diameter.] 



