VAUCHERIA. 51 



especially such species as Inhabit shallow and extended waters, 

 mature and shed their seeds prior to their drying up, and that 

 the special period of their doing this varies in a measure with 

 that of the exhaustion of the water. 



Further research will doubtless disclose many other species 

 in addition to those described to be inhabitants of the 

 fresh waters of Great Britain. Few species of the genus 

 Vaucheria dwell in the sea. They bear, however, a close 

 analogy to the marine genera Bryojjsis, Codium, and especially 

 Ectocarpus. M. Decaisne places the Vaucheria in his class 

 AplosporecBy a class in which the Batrachospermece find a place. 

 They are much more nearly related to his Sunsjjores, than 

 to the family of Batrachosperms. 



a. Vesicles lateral, solitary. 

 1. Vaucheria dichotoma Ag.* 

 Plate IV. Fig. 1. 



Char. " Frond setaceous, dichotomous, fastigiate. Vesicles 

 solitary, globose, sessile, ^^ — Grev. 

 Hooker's Brit. Flor. vol. ii. p. 319. ; Conf. dichotoma, Eng- 

 lish Botany, t. 932. ; Harvey's Manual of British Alga3, 

 p. 147. ; Berkeley's Gleanings ; Dilhvyn's British Con- 

 ferva?, t. 65. 

 Hab. " In jjonds and ditches ; frequent ; annual ; spring 

 and summer." 



" Fronds setaceous, a foot or more in length, dichoto- 

 mously branched, forming wide strata at the bottom of jjools, 

 and frequently fiUing them ; colour, a pale yellowish green, 

 and occasionally dark." — Harv. I much doubt whether this 

 is anything more than a condition of Vaucheria sessilis, the 

 capsule being of precisely the same form as in that species, and 

 upon undoubted specimens of Avhich it is by no means uncom- 

 mon to find solitary capsules. A yellowish or olive green is the 

 colour of all the species of the genus when aged and in seed. 



* The abbreviation of the name of the individual affixed to the specific 

 denomination of any production does not necessarily imply more than the 

 fact, that the person thus alluded to was the first to plat^e that production 

 in the genus with which it is in this work described. 

 E 2 



