462 Fresh- Water Alga of Canada. 



Z. pellucidum. Hass. 



" Char. — Filaments of rather less diameter than those of Z. cur- 

 vatum ; mucous almost transparent. Conjugation parallel. 

 Cells six or seven times as long as broad. Spires indistinct 

 (in our specimen very clearly developed) usually four in num- 

 ber. Sporangia circular, lodged in cells tohich are considera- 

 bly enlarged for their accommodation." Hass. 

 Hass., Brit. F. W. Alg., p. 143, pi. 25, figs. 1 and 2. 

 Hab. — In pools at the Old Race Course, Mile End. 



This is a very curious and beautiful species, and one by no 

 means common either in Europe or Canada. The spires are very 

 distinct, and cross one another at acute angles. We have not 

 seen this plant in conjugation or sporangia, but we have no doubt 

 as to its other characters, and these are sufficiently striking to 

 render it easy of identification. 



Z. decimium. Ag. 



" Char. — Filaments rather fine. Cells twice or thrice as long as 

 broad. Spires two, crossing each other. Granules large. Spo- 

 rangia oval, obtuse, not producing inflation of the cells in 

 which they are lodged." Hass. 

 Hass., Brit. F. W. Alg., p. 144, pi. 23, figs. 3 and 4. Harv. 



Manual, p. 143. 

 Hab. — Frequent in stagnant pools throughout Canada. 



We can only determine our specimens by the length of the 

 eel's, and the number and character of the spires. Concerning 

 the Sporangia we can say nothing from our owu knowledge, but 

 we have no doubt whatever as to the identification of the species 

 It is a very beautiful plant under the microscope, and very dis- 

 tinct in its characters. 



Z.^estivum. Hass.? 



" Char. — Filaments very delicate. Spire single. Cells usually 

 about four times as long as broad, but sometimes much longer 

 and occasionally shorter. Sporangia oval, not producing any 

 inflation of the cells in which they are found" Hass. 



Hass., Brit. F. W. Alg., p. 146, pi. 28, figs. 3 and 4. 



Hab. — Common in pools. 



We have marked this species doubtful, because two of the cha- 



