180 THE NORTH AMERICAN SLIME-MOULDS 



tion open to observation. Probably such is the case; but as a matter 

 of fact a single small Plasmodium at lower levels will sometimes show 

 greater range of variation than were noted on the mountain-side. 

 The cylindric forms were for some reason few, and when noted were 

 short, though often surmounting stems of double the usual length. 



Rostafinski calls this C. friesiana, a name suggested by De Bary. 

 By this name the species was commonly known for many years. More 

 recently some writers prefer C. obtusata Preuss ; but C. obtusata 

 Preuss, as figured by that author (Sturm's Deutsch. FL, PI. 70), is 

 surely more likely Enerthenema papillata, and the author says in his 

 description "capillitio vertice soli innato." Persoon certainly recog- 

 nized the species, and his description, though brief, is yet applicable 

 to no other European species. There seems no reason why the name 

 he gave should not be permanently adopted. Rostafinski's figure, 

 Tab. XIII., shows an ellipsoidal sporangium, not cylindric. 



On the lower levels of the Mississippi valley, the species is not 

 common. Possibly overlooked by reason of its minuteness. 



Massachusetts, Pennsylvania, Ohio, Iowa, Colorado, North Caro- 

 lina, Missouri. 



9. COMATRICHA .^QUALIS Peek. 

 Plate VI., Figs. ^, Z a, Z b, I c, ^ d\ and Plate XVIII., Figs. 13, 13 a, 13 b. 

 1890. Comatricha equalis Peck., Rep. N. Y. Mus., XXXI., p. 42. 



Sporangia gregarious, seldom erect, usually inclined, curved or 

 nodding, dark brown, becoming violet, cylindric, acuminate-obtuse, 

 stipitate; stipe about half the total height, 2-2^ mm., black, pol- 

 ished, even; hypothallus well developed, brown, continuous; colu- 

 mella black, tapering gradually, and attaining almost the summit of 

 the sporangium; capillitium dense, of flexuous tawny threads which, 

 by repeated branching, form an intricate network, the free extremities 

 numerous, short, and pale ; spores dark violaceous, distinctly warted, 

 7.5-8 p.. 



A very graceful, elegant species, related to C. pulchella and C. 

 persoonii, but distinct by its much greater size and smaller spores. 

 The specimens before show us the perfection of beauty in this genus; 



