NOSTOCHINE^. 115 



This is unknown to me. It seems to be closely allied to the preceding species, if it 

 be distinct. The plicae and reticulations observed do not appear to be characters of 

 much value for the discrimination of species among these gelatinous plants. 



6. NosTOC microscopicum, Carm. ; fronds densely aggregated, very minute, globose 

 or oblong, immersed in a blackish crust ; filaments few. Carm. in Hook. Brit. Fl. 2, 

 p. 399. ffarv. Man. Ed. 1, jo. 184. N. muscorum, Hass. Br. Fr. Wat. Alg. p. 292, 

 t.l^fig.4.. 



Hab. " Stones in a small stream, Baffin's Bay, Dr. Sutherland^ fide Prof. Dickie. 



I have not seen American specimens. In Britain this species grows among mosses 

 on exposed calcareous rocks, but not in water. The above specific character is taken from 

 the British plant. The fronds are rarely more than the tenth of an inch in diameter, 

 and contain two or three beaded filaments lying in a copious transparent jelly. 



7. NoSTOC flagelliforme, Berk, and Curt. ; terrestrial ; frond cartilaginous, linear, 

 very narrow, compressed and often channelled, much branched, irregularly dichotomous ; 

 branches solid, densely fiUed with moniliform curved threads. Berk, and Curt. 

 No. 3809. 



Hab. On naked aluminous soil, at San Pedro, Texas, Mr. Charles Wright (v. s.) 



Fronds several inches in length, half a line in diameter, lying prostrate on the 

 surface of the soil, much branched in an irregularly dichotomous manner : branches 

 exactly linear, compressed, often channelled on one or both sides, thinned in the middle 

 and incrassated to the edge. Substance firm and elastic, cartilaginous, solid, densely 

 filled with moniliform, curved or curled, interlaced threads, which are set longitudinally 

 in the frond, and lie nearly parallel to each other. Colour dark olive. 



A very curious and most distinctly marked species, differing from others of this 

 genus, much in the same manner that Chcetophora endivicefoUa does from the ordinary 

 globose forms of Chcetophora. 



