225 



FAM. XL HYDRODICTYONE^E. 



21. HYDRODICTYON Roth. 



Char. Cells arranged in the form of a pentagon, an aggre- 

 gation of a number of these pentagonal meshes, going to 

 form an entire plant. Zoospores numerous in each cell, 

 and uniting together before the absorption of the parent 

 cell membrane. 



Derivation. From vSoy>, water, and SIKTVOV, a net. 



1. HYDRODICTYON UTRICULATUM Roth. 



Plate LVIII. 

 Char. Same as those of the genus. 



Harv. in Hook. Br. Fl. vol. ii. p. 359. Conf. reticulata, 

 E. B. t. 1687. ; Dillw. t. 97.; Vauch. Conf. d'Eau douce; 

 Harv. Manual, p. 140. 



Hab. In ditches and pools in the midland and southern 

 counties of England. In a pond in the Botanic Garden 

 at Cambridge, where it has existed for many years : 

 Rev. Prof. Henslmv. Not found in Scotland or Ireland 

 hitherto. 



Hydrodictyon utriculatum is one of the most remarkable 

 of the freshwater Alga. The credit of the discovery of the 

 singular reproduction of this species is due entirely to 

 Vaucher, whose account of it is so clear and well expressed 

 that I cannot do better than translate his remarks : Each of 

 the fine filets (cells) which form the pentagon begins to swell 

 a little, principally at the extremities, then it is separated 

 from the others not by a rupture, properly so called, but by 



Q 



