1 10 THE NORTH AMERICAN SLIME-MOULDS 



and distinct, though sometimes closely placed and generally 

 rising from a common hypothallus. 



Key to the Genera of the Stemoniteae 



A. Fructification aethalioid ; capillitium charged with vesicles, 



i. BREFELDIA 



B. Sporangia distinct, or nearly so. 



a. Stipe and columella jet black. 



1. Capillitium so united as to form a surface net, 2. STEMONITIS 



2. Capillitial branch-tips free . . .3. COMATRICHA 



b. Stipe and columella whitish ; calcareous . . 4. DIACHEA 



i. Brefeldia Rostafinski. 

 1873. Brefeldia Rostafinski, Versuch, p. 8. 



Sporangia occupying in the aethalium several layers, those of 

 the median, and especially of the lowest layers, furnished with 

 columella which blend beneath ; capillitium threads in the lowest 

 layers arising from the columella, in the upper extending radi- 

 ately between the individual sporangia, and united at the sporan- 

 gial limits by means of rather large inflated cells. 



The genus Brefeldia is, like some others, difficult to dispose 

 of in any scheme of classification where linear sequence must 

 be followed. Rostafinski placed it in an order by itself. Its 

 relationships are on the one hand with Amaurochcete and Reticu- 

 laria, and on the other with the Stemonitece, though easily dis- 

 tinguished from either. It is intermediate to Amaurochcste and 



o 



Stemonitis, and withal, as it appears to us, a little nearer the 

 latter, as the limits of the individual sporangia are in Brefeldia 

 pretty well defined. 



i. BREFELDIA MAXIMA (Fries} Rost. 



FRONTISPIECE ; PLATE V., Figs. 7, 7 a, 7 b, 



1825. Reticularia maxima Fries, Syst. Orb. Veg., I., p. 147. 

 1875. Brefeldia maxima (Fries) Rost., Versuch., p. 8. 



large, two to ten inches, papillate above, violet 

 black at first, then purple or purple brown, developed upon a 



