LEOCARPUS 8 1 



throughout, or nearly so, the meshes large and the threads or 

 tubules broad; columella none, although a pseudo-columella 

 may sometimes be detected. 



This genus was by Link established on characters purely 

 external, and these are perhaps sufficient to distinguish it yet. 

 Rostafinski supplemented Link's definition by calling attention 

 to the peculiar character of the capillitium and to microscopic 

 characters in general. The outer peridium is very thick and 

 strong, unlike any similar structure in the group. Pkysarum 

 citrinellum Pk. approaches Leocarpus in its double peridium, but 

 the outer wall is different, to say nothing of the capillitium. In 

 dehiscence and structure there is also some resemblance to some 

 species of Diderma, and by Persoon and Fries it was so referred, 

 but the capillitium is again definitive. 



i. LEOCARPUS FRAGILIS (Dickson) Rost. 

 PLATE VIII., Figs. 3, 3 a, 3 b. 



1785. Lycoperdon fragile Dickson, Fasc, PI. Crypt. Brit., I., p. 25. 



1795. Diderma vernicosuin Persoon, Ust. Ann. Bot., XV., p. 34. 



1809. Leocarpus vernicosus Link, Diss., I., p. 25. 



1875. Leocarpus fragilis (Dicks.) Rost., Man., p. 132. 



Sporangia gregarious or clustered, sessile or stipitate, obo- 

 void, rusty or spadiceous yellow, shining ; peridium opening at 

 maturity in somewhat stellate fashion ; stipe filiform, white or 

 yellow, weak and short; spores dull black, spinulose, .oi2-.oi4/-t. 



A common species, distributed through all the world, Iowa to 

 Tasmania. Recognizable at sight by the form and color of the 

 sporangia. In shape and posture these resemble the eggs of 

 certain insects, and, occurring upon dead leaves, generally 

 where these have drifted against a rotten log, they might per- 

 chance be mistaken for such structures. With no other Slime- 

 mould are they likely to be confused. The outer peridium 

 opens irregularly or more rarely stellately. At centre of the 

 capillitium is a calcareous core. The plasmodium is yellowish 

 white, spread in rich and beautiful reticulations. N. A. F., 

 1123. 



G 



