CLOSTERIUM. 367 



9. COSMARIUM QUADRATUM Ralfs. 



Plate LXXXVI. Figs. 11. and 12. 



Chai', Fronds about twice as long as broad. Segments qua- 

 drate, in front view sliglitly compressed, smooth. 



Kalfs, 1. c. vol. xlv. t. 11. f. 8. ; Jenner, 1. c. p. 196. 

 Hab. Eustliall Common, near Tunbridge AVells : Mr. 

 Jenner. Dolgelly : Mr. Ralfs. 



The front view of the segments is somewhat quadrangular, 

 the distal or free angles being slightly rounded, and the 

 proximate, protuberant. 



10. COSMARIUM CUCURBITA Brcb. 



Plate LXXXVI. Fig. 7. 



Char. Fronds small, about twice as long as broad, cylindrical, 



with a slight constriction in the centre, minutehj jninctated. 



End view circular. 

 Ralfs, in Annals, vol. xiv. ; Jenner, in Flora of Tunbridge 



Wells, p. 196. Cosmarium Cucurbita Desm., No. 1103. 

 Hab. Dolgelly ; Mr. Ralfs. Ashdown Forest and 



Greatham bogs, near Pulborough : 3Ii\ Jenner. 



This species approaches rather closely to Cosmarium cylin- 

 drum Ralfs, but the frond in that species is distinctly den- 

 tated, whereas in C. Cticurbita Brcb. it is merely dotted : 

 it also has a great resemblance to Clostcrium cylindrus, but in 

 that plant the puncta are described as arranged in longitudinal 

 lines, whereas in Cosmarium Cucurbita they are scattered. 



59. CLOSTERIUM Nitzsch. 



Char. Fronds elongated, mostly crescentic, sometimes con- 

 jugating; each formed of two similar segments, ichich 

 unite without constriction, and the free extremity of each 



