DIANEMA 251 



slender as those of the Dianema. The spores are quite different, those 

 of the Dianema being large, averaging 11 /x, and distinctly spinulose, 

 the spines visible over the entire surface; the spores of the Lamproder- 

 mopsis are smaller, averaging about 9 /jl in our material, and the sur- 

 face is covered with almost invisible spines apparently embedded in 

 a gelatinous outer wall so that they are visible only at the margins. 

 British Columbia, Washington. 



2. Dianema harveyi Rex 



Proc. Acad. Nat. Sc. Phila. 1891 : 397. 

 PI. XVI, Figs. 418, 419. 



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

 pressed, sessile, dull red or iridescent-bronze, 0.5-2 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 free, yellow in mass, by transmitted light pale 

 yellowish, spiny, 8-10 p. Plasmodium white. 



Rare. On dead wood, Maine, Colorado; Great Britain. Reported as 

 locally abundant in Scotland. 



3. Dianema depressum List. 



Mycetozoa 204. 1894. 

 PI. XVI, Figs. 420, 421, 422. 



1891. Cornuvia depressa List., Jour. Bot. 29 : 264. 



Fructification pulvinate or plasmodiocarpous, flattened, 2-10 mm. 

 wide, about 0.3 mm. thick, gray-brown, glossy; wall membranous, 

 smooth or minutely reticulated, translucent, yellowish gray or lilac, 

 marked on the inner side with the persistent ends of the capillitium; 

 capillitium profuse, of pale, yellowish gray rigid threads, 0.5-2 n thick, 

 minutely papillose on one side, united above and below into pencil-like 

 clusters, at length breaking away as an elastic web ; spores free, in mass 

 lilac-gray or drab, pale yellowish gray under the lens, closely reticu- 

 lated over the greater part of the surface, the remaining part marked 

 with broken or loose reticulation, 6-9 /x. Plasmodium white or rosy. 



On wood. Rare in North America, known only from Washington and 

 Oregon. Also Europe, Japan. 



4. Dianema corticatum List. 



Mycetozoa 205. 1894. 

 PI. XVI, Fig. 417; PI. XXI, Fig. 562. 



Sporangia sometimes flat-hemispheric, more often ill-defined, united 

 in irregular, depressed, netted plasmodiocarps, generally dull brown; 



