LYNGBYA. 223 



Hal. Growing on stones in a mountain rivulet at Bal- 

 lantrae, Ayrshire: Mr. W. Thompson. 



This is clearly a Lyngbya, and the most minute species of 

 the genus with which I am acquainted. It is described as 

 forming " beautiful, glossy, dark green tufts." 



6. LYNGBYA FLOCCOSA Hass. 

 Plate LX. Figs. 1, 2. 



Char. Filaments of smaller diameter than those of L. muralis. 

 Cells at first cylindrical, subsequently beaded, rather longer 

 than broad. 



Conf. fioccosa Ag. Conf. fugacissima Dillw. Supp., t. B. 

 C.floccosa Harv. Manual, p. 126. 



This species is very distinct and abundant, being found 

 in great quantities in almost all ponds, on heaths and bogs. 

 The filaments are rarely attached, are highly mucous and 

 tenacious. When kept in water it does not quickly pass to 

 decay. Specimens are often met with, which when placed 

 under the microscope appear quite colourless, the endochrome 

 having escaped from the cells. 



7. LYNGBYA PUNCTALIS Hass. 



Plate LX. Fig. 4. 



Char. Filaments of less diameter than those of Lyngbya 

 fioccosa, very mucous. Cells two or two and a half times 



as long as broad, slightly contracted. Endochrome at 

 first quadrangular, not filling the entire cavity of the cell, 



arranged usually in two separate masses, but sometimes 



there is but one ; subsequently the cells becoming inflated, 



the endochrome assumes a spherical form. 



Sph&roplea punctalis Berk. Glean. Alg. t. 3. fig. 2. Conf. 

 punctalis Dillw. t. 51. Sph. punctalis Harv. in Manual, 

 p. 144. 



