238 THE NORTH AMERICAN SLIME-MOULDS 



ing above irregularly; capillitium of long flexuous, coiling, simple or 

 little dividing threads, nearly smooth, with infrequent attachments to 

 the peridial wall ; spores in mass yellowish, transparent under the 

 lens, delicately verruculose, 10-12 /x. 



One of the handsomer species of the present group. So far a 

 Pacific coast form. California, Oregon, Washington ; reported from 

 Chile. 



Dianema Rex 



1891. Dianema harveyi Rex, Proc. P/iil. Acad., p. 397. 



Sporangia simple or plasmodiocarpous; capillitium composed of 

 threads without characteristic thickenings running entirely across the 

 sporangium attached both to the base and to the opposite wall, not 

 joined to form a network. 



Key to Species of Dianema 



A. Sporangia distinct, iridescent I. D. harveyi 



B. Fructification more or less plasmodiocarpous, dull brown 



2. D. corticatum 



C. Sporangia, some of them stipitate . . . 3. D. andersoni 



1. Dianema harveyi Rex. 



Plate XVI., Figs. 5 and 5 b. 

 1891. Dianema harveyi Rex, Proc. PhiL Acad., p. 397. 



Sporangia gregarious, generally rounded or cushion-shaped, de- 

 pressed, sessile, iridescent bronze, 1 mm. in diameter; peridium thin, 

 translucent, opening irregularly; capillitium of simple threads, not 

 netted, but often forked two or three times, taut, running from base 

 to top; spores yellow, by transmitted light pale yellowish, minutely 

 roughened, 8-10 p.. 



This interesting species was collected in Orono, Maine, in 1889, 

 by Professor F. L. Harvey, and so far as can be learned has not 

 been taken since. Mr. Lister records two species from England which 

 he refers to this genus. As to its systematic place, Dr. Rex says, /. c. 

 "It stands as a single representative of a new and separate family 

 adjoining the Perichaenacae in the order Calonemeae of Rosta- 

 finski." 



Rare. Maine. 



