230 THE NORTH AMERICAN SLIME-MOULDS 



Recognizable by its small size and peculiar color, that of bright 

 copper, although this fades somewhat with age, and the metallic tints 

 are then lacking. Related to the preceding and in specimens having 

 globular sporangia closely resembling it ; but the ground color in C. 

 languescens is always darker, and the stipe proportionally much 

 longer. In habit the sporangia are widely scattered, much more 

 than is common in the species of this genus. Miss Lister, 2nd ed. 

 regards this as a var. of No. 15. 



Comparatively rare. Before us is one very small colony of sporan- 

 gia from Iowa, one from Ohio, and a large number from Missouri. 

 If one may judge from the material at hand, the favorite habitat is 

 very rotten basswood, Tilia americana. 



2. Dictydium (Schrad.) Rost. 



Sporangia distinct, gregarious, globose or depressed-globose, stipi- 

 tate, cernuous; the peridium very delicate, evanescent, thickened on 

 the inside by numerous meridional costae which are joined at fre- 

 quent intervals by fine transverse threads more or less parallel to 

 each other, forming a persistent network of rectangular meshes. 



The ribs or costae of the spore-case radiate from the top of the stipe 

 and unite again at the top of the sporangium in a feeble, irregular 

 net. Schrader, Nov. Gen. PL, p. 11, 1797, applied the name Dic- 

 tydium to all Cribraria-like species in which the calyculus was want- 

 ing. Fries follows this, Syst, Myc, III., p. 164. Rostafinski, Ver- 

 suchj p. 5, Mon., p. 229, first correctly limits the genus and sepa- 

 rates it from Cribraria. 1873-75. 



A single species is ^videly distributed throughout the world, — 



1. Dictydium cancellatum {Batsch) Macbr. 



Plate I., Figs. 6, 6 a and Plate XIX., Figs. \, \a, \h, \ c, 2, 3. 



1789. Mucor cancellatus Batsch, Elench. Fung., II., p. 131. 



1797. Dictydium umhilicatum Schrad., Nov. Gen. PL, p. 11, 



1801. Cribraria cernua Pers., Syn., p. 189. 



1816. Dictydium cernuum Nees, Syst. d. Pilz., p. 117. 



1875. Dictydium cernuum (Pers.) Rost., Mon., p. 229. 



1893. Dictydium longipes Morg., Cin. Soc. Jour., p. 17, in part. 



Sporangia gregarious, depressed globose, nodding, the apex at 



