244 THE NORTH AMERICAN SLIME-MOULDS 



A very handsome little species occuring rarely with us, or perhaps 

 overlooked by virtue of its protective coloration. Found sometimes 

 on the inner side of the bark where the latter has separated, but 

 not yet wholly parted company with the wood. In such situations 

 the tiny sporangia are so nearly quite the color of the moist sub- 

 stratum as to escape all but the closest scrutiny. The dehiscence 

 is very remarkable, characteristic, beautiful. Black, brown, chestnut, 

 and gold are harmoniously blended, in the opening coffers. Prior 

 to maturity the future line of fission is plainly indicated by the differ- 

 ence in color. 



This is clearly the species found by Batsch "ligni demortui putri- 

 di in interiore corticis pagina." Bulliard has also described and 

 figured the species, Sphaerocarpus sessilis t. 417, Fig. V. 



The capillitium is nearly smooth ; the spores are only slightly 

 roughened by minute warts. 



Apparently not common. Iowa, Missouri ; Black Hills, South 

 Dakota ; Canada ; — Miss Currie. 



4. Perichaena marginata Schiveinitz. 



1831. Perichaena marginata Schw., A^. A. F., No. 2319, p. 258. 



Sporangia depressed, globose, polygonal as they become approximate 

 or crowded, hoary canescent, sessile ; peridium rather thick, persistent, 

 circumscissile in dehiscence, covered without by minute whitish cal- 

 careous (?) scales, within punctate by the imprint of the spores; 

 hypothallus distinct, white ; capillitium scant or none ! Spores in 

 mass dull yellow, by transmitted light pale, nearly smooth, 14—15 /u.. 



Lister, following Rostafinski, includes this form with the pre- 

 ceding. The differences between the two forms are, it seems to us, 

 sufficient to make convenient their separation as by Schwcinitz. Apart 

 from the peculiar incrustation in the present species, the larger 

 spores, and especially the peculiar white hypothallus, are distinctive. 

 The method of dehiscence is also different. In P. corticalis the 

 line of cleavage before spore dispersal is indicated by a definite band 

 surrounding the sporangium. Nothing similar appears in the gray 

 specimens of the present form, although the dehiscence is quite as 

 certainly circumscissile. The habitat in American specimens is the 



