IOS THE NORTH AMERICAN SLIME-MOULDS 



length jet black, when it is covered by a thin papery silvery 

 membrane ; hypothallus generally well developed ; capillitium 

 dendroid, consisting of rather stout branches which rise ir- 

 regularly more or less vertically from the hypothallus, branch 

 repeatedly, often anastomose to form a network, especially 

 toward the periphery ; spores black. 

 A single genus 



i. Amaurochsete Rostafinski. 



1873. Amaurochcete Rost., Versuch., p. 8. 



The genus Amaitrochate as denned by Rostafinski and the 

 genus Reticularia as represented by R. lycoperdon Bull, stand, 

 no doubt, very near together. The capillitial structure in the 

 two forms is similar, the mode of development and habit of 

 growth are also similar; they differ in color and in the nature 

 of the epispore. The two forms seem to us to occupy a position 

 near the dividing point from which radiate two distinct lines of 

 differentiation ; the one, by way of Stcmonitis and Comatricha, 

 finds its extreme in Lamproderma and Encrthcncma ; the other, 

 through Enteridium and Tubifcra, reaches its climax among the 

 Trickias. To the first of these series belongs AmaurochcKte^ 

 while the color and sculptured or reticulate spores of Reticularia 

 seem to ally it more nearly with the latter series. If it be sug- 

 gested that it is inconsistent to esteem a structure, confessedly 

 similar in the two genera, the so-called capillitium, as at once 

 related to the columella, as in Stcmonitis^ and the peridium, as 

 in Tubifcra, it is necessary only to recall the fact that in the 

 best case all such structures of the fructification are but forms 

 of the residue after the formation of the spores ; so that it is per- 

 fectly within the lines of present knowledge to maintain that 

 the ascending dendroid capillitial filaments of Amaurochcete are 

 the precursors of stemonite columellae, while the flat expanded 

 branches of similar structures in Reticularia become later on the 

 peridial walls of distinct saccate sporangia. There are before 

 us specimens of A. atra, in which the capillitium is all vertical 



