252 CRYPTOGAMIA 



Hab* On the wood works of mill dams, and on banks expo- 

 sed lo the constant trickling of water, common. 



" One of the most common species of the genus, inhabiting 

 places where there is a constant supply of trickling moisture, 

 especially upon a muddy or clayey surface. The masses 

 which it forms often become pendant by their own weight, 

 holding water like a sponge, and presenting the most beau- 

 tiful green surface. Immediately beneath the surface, 

 however, the filaments become pale, and at last colourless." 

 GREVILLE. 



There is a Vaucheria very abundant in our ditches in spring, 

 floating on the surface in large dense green or yellowish- 

 green masses, where it is supported by the air entangled 

 in its meshes. The filaments are long and coarse, simple 

 or branched irregularly towards their top, often radiating at 

 the margins, and turning whitish in decay. Not having 

 found it in fruit, I am uncertain of the species. It is, 

 however, the Conferva furcata of WITHERING, iv. 145; and 

 is very well represented by DILLENIUS in tab. 3. f. 10. of 

 the Historia Muscorum. 



4. V. geminata, green, in floating entangled masses ; filaments 

 dichotomously branched, slender ; vesicles ovate, opposite, in 

 pairs, attached by little partial stalks to the side of a horn-like 



common stalk GREV. Alg. Brit. 193. t. 19. f. 3. Eng. Eot. 



t. 1766. 



Hab. In ditches near Berwick. Autumn. 



In stubble fields in autumn I find a species which agrees 

 with V. geminata in its fructification. The filaments are 

 creeping, entangled, flexuose, sparingly and irregularly 

 branched. The vesicles are globular, shortly pedicled, 

 placed on the sides of a common stalk, the point of which 

 rises up straight between them. 



158. CONFERVA. 



* Filaments simple. 



1. C. confervicolci) glaucous green ; filaments unbranched, short- 

 ish, tufted, taper-pointed ; articulations very short DILLW. Syn. 

 39. t. 8. and t. A. Eng. Eot. t. 2576. 



Hab. Parasitical on Gracillaria purpurascens in numerous 

 little scattered tufts. Berwick Bay. 

 4 



