262 



FAM. XIV. RIVULAREJL 



Char. Frond usually gelatinous, lubricous, and definite, in 

 which are embedded filaments often fiagelliform, simple, or 

 spuriously branched, hilted below, the hilts being formed 

 of an enlarged cell, connected to the filaments by a narrow 

 neck, and filled with endochrome. Sheaths in which the 

 filaments are enclosed, sometimes saccate below, above at- 

 tenuated and open. 



No very exact observations have as yet been made upon 

 the reproduction of this family. Do not the enlarged cells 

 which terminate the base of the filaments correspond in 

 function with those of the Nostochinece ? In the setigerous 

 elongation of the filaments a resemblance to Chcetophora is 

 manifested. Certain species exhibit a relation to the Scyto- 

 nemece. 



31. RIVULARIA. 



Section i. RIVULARIA Roth. 



Char. Frond wart-shaped, rarely encrusting, coriaceous. Fila- 

 ments close, set firmly, adherent, spuriously branched, 

 radiating. 



Linkia Lyngb. 



1. RIVULARIA PISUM Ag. 



Char. Frond globose, smooth, shining, dark green. Filaments 

 dichotomous, firmly united. 



Harv. in Hook. Br. Fl. vol. ii. p. 392. ; Berk., Glean. Alg. 

 t. 2. p. 2. 



Hab. On aquatic plants in subalpine streamlets, Appin: 

 Captain Carmichael. Cheshunt Common : A. H. H. 



