r 



/ 



54 SIPHONED. 



seed-vessel, which is of smaller size, rests almost immediately 

 on the incurved anther. 



Found in fructification, according to Vaucher, in the 

 autumn ; my specimens were obtained in a hedge at 

 Cheshunt in March, and were also in fructification. 



b. Vesicles lateral^ sessile, geminate. 



6. Vaucheria aversa Hass. 



Plate VI. Fig. 5. 



Char. Capsules usually in pairs, and in the form of a 

 bircTs head, ivith the heaks averted from each other. Spo- 

 rangia circular, not entirely filling the cavity of the capsule. 



Hassall, in Annals of Nat. Hist. vol. xi. p. 429. 



Hab. Vicinity of Cheshunt. 



I have now met with this species repeatedly ; it is one of 

 the best marked and most peculiar of the genus, the 

 beaks of the capsules being turned in opposite directions at 

 once, distinguish it from all other known species, in which, 

 when the vesicles are in pairs, they are directed towards 

 each other. This averted position of the capsules renders 

 the existence of a distinct horn or anther essential for each. 

 In the form of the seed-vessels, and in the circumstance of the 

 sporangia not filling the entire cavity, the species resembles 

 Vaucheria ornithocephala. 



7. Vaucheria ornithocephala Ag. 



Plate VI. Fig. 4. 



Char. " Vesicles binate or quaternate, with a short beak, and 

 pellucid border, upon short, straight peduncles. ^^ — Harv. 



Grev. Alg. Brit. p. 193. ; Hooker, Brit. Flor. p. 320. ; Conf. 

 vesicata Dilhv. Brit. Conf. t. 74. ; Harv. Manual Brit. 

 Algae, p. 148. 



