292 NOSTOCHINEiE. 



Hyclroph. p. 200. t. 68 a. ; Harv. in Hook. Br. Fl. p. 399. ; 

 also in Manual, p. 184. ; Meneghini, loc. cit. p. 114. 



Hah. In freshwater pools near the coast ; rivulet near 

 Torquay : Sir W. J. Hooker. Appin : Captaiji Car- 

 rtiichael. 



• <f Fronds unattached, scattered at random in the clefts of 



the rocks, globular, smooth, olive-green, diaphanous, from ^ to 

 IJ inches in diameter, the larger ones generally compressed, 

 hollowed, and sometimes ruptured." — Carmichael. 



The filaments, as remarked in the description of the pre- 

 ceding species, resemble those of Nostoc verrucosum in all, save 

 size, being larger than in that species. The reproductive cells 

 are rarely 23roduced. 



8. Nostoc muscorum Ag. 



Plate LXXIV. Fig. 4. 



Char. Frond tuberculate, suhcoriaceous, variable in shape. 

 Filaments much curved, moidliform, exceedingly slender. 



Ag. Disp. p. 44. ; Ag. Syn. p. 132.; Syst. p. 19. ; Harv. 

 in Hook. Br. Fl. p. 399. N. rmiscorum Harv., in 

 Manual, p. 183. N. microscopicum Carm., MS.; Harv. 

 in Manual, p. 184. ; Meneghini, Nostochinearum Italica- 

 rum, p. 119. 



Hob. N. muscorum, on calcareous rocks, and the mosses 



/^^ which cover them, Appin : Captain Carmichael. — N. 



-f ^ , microscopicum, on exposed calcareous rocks among 



/T ' ' mosses, Appin : Captain Carmichael. Near Youghal : 



' ^'" Miss Ball. Wilderness, near Clonmel : W. H. Harvey. 



''' ' Clayey banks, co. Antrim : Mr. Moore. 



^ I have examined several of Carmichael's specnnens of this 



^ ^yjcfy,^/ Nostoc, and compared them with others of Nostoc micro- 



"'^*'" scopicum Carm., and I entertain no doubt of the specific 



y^ identity of both. All the specimens which I have received 



of the former have consisted not of single fronds, but of an 



ao-orreo-ation of numerous smaller fronds of various sizes and 





