464 Fresh-Water Alga? of Canada. 



habitants of fresh water, and are probablj distributed very widely 

 over every region of the world. They have been found by Drs. 

 Hooker and Thompson on the Southern Himalayas, and in the 

 lower parts of India. The genus Zygnema ascends as high as 

 15,000 feet on the Himalayas. Species identical with the Euro- 

 pean are found in almost every part of the United States and 

 Canada. South America is said to yield scarcely a trace of them, 

 but this may be accounted for from the fact that few botanical 

 explorers of these regions have thought the lowly Algae worth 

 observing. We doubt not that a diligent Algologist would reap 

 a rich harvest of curious species in the everglades of that region, 

 and in the waters and tributaries of its mighty rivers. 



Passing over the other genera of the family Conjugated, and 

 also the family Cystqspermed, of which we have found no spe- 

 cimens as yet in Canada, we come to — 



Fam. X.— MONOCYSTE^E. 



This family consists of three genera of fresh-water Algss, viz., 

 Cladophora, Coleochwte, and Lijnghya. In the species there 

 is no union of the cells or intermingling of their contents ; 

 each cell contains all that is requisite for its reproduction 

 in the way of fertilizing vesicles and zoospores. When the 

 zoospores have been fertilized the cells swell up, until, by the 

 increase of the size of the zoospores, the cell walls are ruptured, 

 and the zoospores escape through the aperture thus produced. 

 The plants of this family are for the most part attached to sub- 

 merged stones or wood, and grow by the lateral and longitudinal 

 development of their cells, aud the production of new branches at 

 the articulations. 



SUB-FAM. I. — ClOBOPHORED. 



Genus 1. — Clabophora. Kiitz. 

 " Char. — Filaments attached, much branched, not setigerous, and 



not invested with secondary celhr Hass. 

 Derivation. — From hlados a branch, and phoreo to bear. 



This genus is very marked, and easily distinguished ; for the 

 most part its species are prolifically branched, and very simple in 

 the structure of their cells. 



Clabophora glomerata. Dillw. 

 " Char. — Filaments tufted, bushy; somewhat bright green, shilling. 

 Branches crowded, irregular, erect; the ultimate ramuli 

 secund, sub-fasiculate. Articulations four and eight times 

 longer than broad." Hass. 



