BY G. I. PLAYFAIR. 499 



to be found in the propagation of all tliese genera by autospores. 

 To l)egin with, the autospores differ sHghtly (and sometimes more 

 tlian slightly) from the parent-cell, and their subsequent develop- 

 ment along diverging lines will, no doubt, result in more oi' less 

 widely differing forms. 



Another interesting point to be noted is, that now and again 

 one or other of these forms would be recorded at the scmip time 

 from some other pool connected with an entirely different water- 

 shed, or even in another part of the neighbourhood, but thev 

 were just as evanescent. 



MYXOPHYCE^. 



Syn. Phycochromojjhycefe^ Cyanophycece, Schizoi^hycpw. 

 Fam . CHROOCOCCACE.^J . 

 Genus Syxechococcus ^ag. 

 Syxechococcus grandis, n.sp. (Text-fig. 1 ). 



Cellulse magnse, crasspe, oblongo-o vales; apicibus 

 late-rotundatis ; lateribus arcuatis ; cytoplasmate l^'^'^'. 

 jeruginoso, gi-anuloso. /l;'\^«-'*-i"4;^l 



Long. 33, lat. L>3//. Lismore (345). 



Of Nageli's three species (Gatt. einz. Alg., p. 5 6, 

 T. i.E, f.1-3), none are over 20/x long. S. major 

 Schroter, the nearest in size, is cylindrical. See G. Text-fig. 1." 

 8. West, Br. Frw. Alg., p. 347, f.l61D, E. 



Genus M e r i s M o p e d i u m Meyen. 

 Merismopedium punctatum Meyen. (Text-fig. 2^). 



In Wiegm., Archiv, 1839, p. 67, sec. Rabenhorst, Fl. Eur. Alg.^ 

 ii., p. 57. »Syn., J/. KiUzingii Nag., I.e., p.55, T. i.D, f.2. Con- 

 tents generally pale blue. Usually found in our waters in isolated 

 sets of four cells. As figured, however, out of weeds in the river, 

 the cells were in large sheets but still semi-detached in coenobia 

 of 4. 



Cell. diam. 2/x. Lismore, Richmond R. (272). 



* Synechococciis grandis, n.sp., ( x 660), 



