LYNGBYA. 223 



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

 lautrae, Ayrshire: Mr. W. Thompson. 



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

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

 forming " beautiful, glossy, dark green tufts." 



6. Ltngbya floccosa Hass. 



Plate LX. Figs. 1, 2. 



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

 Cells at first cylindrical, subsequently headed, rather longer 

 than broad. 

 Conf. floccosa Ag. Conf fugacissima Dillw. Sup})., t. B. 

 C. floccosa Harv. Manual, p. 126. 



This sjjecies 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 Avater it does not quickly pass to 

 decay. Specimens are often met with, which when placed 

 under the microscope appear quite colourless, the cndochrome 

 having escaped from the cells. 



7. Lyngbya punctalis Hass. 

 Plate LX. Fig. 4. 



Char. Filaments of less diameter than those of Lyngbya 

 floccosa, very mucous. Cells two or two and a half tiynes 

 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 cndochrome assumes a spherical form. 

 Sphccroplca piinctalis Berk. Glean. Alg. t. 3. fig. 2. Conf. 

 punctalis Dillw. t. 51. Sph. punctalis Ilarv. in jNIanual, 

 p. 144. 



