à. 
204 RECENT RESEARCHES IN THE DIATOMACES. 
therefore placed under this new genus. The genera Donkinia (Pritch.), 
Amphiprora (Ehren.), and Amphitropis (Rab.), by some comprehended in 
the Naviculacee, are considered by our author to be a group nearly related 
hi } ied h 
Grunow’s natural group of Limose. Whether the circumstances referred 
to are sufficient to justify the establishment of a new genus, I leave my 
readers to form their own Opinion. 
Pinnularia (Ehren.).—T 
Navicula by the fact that the strie in the former are uninterrupted or cos- 
» as is the common designation, whereas in the latter they are resolvable 
into dots. This distinction some later writers consider ient, a 
runow, Schuman, Ralfs Heiberg, Cleve, who have therefore included 
the spe Pinnu in the genus Navicul fitzer, however, rë- 
whereas in the Pinnularie, between the deep broad striw, fine lines afe 
interposed. These finer lines referred to by Schuman, Dr. Pfitzer has 
h 
ese 
never been able to discover, and my experience coincides with his. 
