194 THE MYXOMYCETES 



are very uniformly 14-16 /x. In a collection from Rumania they are 

 even more uniform in size, almost all falling between 14.4 and 15.2 ix. 

 Colorado; Europe. Mainly Alpine. 



2. Lamproderma cristatum Meylan 



Bull. Soc. Vaud. Sc. Nat. 53 : 457. 1921. 

 PI. XIII, Fig. 311. 



Sporangia spherical, sessile or with a very short stalk, 1-1.5 mm. in 

 diameter; peridium thin, membranous, dark gray, early disappearing; 

 capillitium rather pale, gray or purplish; spores globose, dark purplish, 

 the surface covered with vesicular, warted crests, appearing more or 

 less reticulate under the lower powers of the microscope, 12-15 lx. 



The spores are unlike those of any other slime mold. Those of our 

 material, sent by M. Meylan, have the crests smaller and more 

 densely aggregated than suggested by his illustration or that of 

 Miss Lister, pi. 216, h, and measuring 14-15 lx. 



Switzerland. 



3. Lamproderma atrosporum Meylan 



Bull. Soc. Vaud. Sc. Nat. 46 : 51. 1910. 

 PL XIII, Figs. 312, 313. 



Sporangia sessile or stalked, globose or oval, 1-1.3 mm. in diameter; 

 stalks, when present, not exceeding height of sporangia; peridium 

 fragile, not membranous, fugacious, breaking up into small fragments 

 some of which adhere to the capillitium, rarely membranous and per- 

 sistent at base, very dark with silvery sheen; capillitium black or 

 very dark brown, showing no trace of violet; columella slender, ex- 

 ceeding the middle; spores dark, strongly warted, the warts arranged 

 in reticulate lines over a portion of the surface of most of the spores, 

 11-15 Li. Plasmodium black. 



There is wide variation in the spore markings, ranging from a nearly 

 complete reticulation to a mere trace. 



G. Lister and Howard (Jour. Bot. 57 : 25, 27, 1919) describe from 

 England the varieties debile and anglicum, paler in color. 



Oregon; Switzerland, England. 



4. Lamproderma echintjlatum {Berk) Rost. 



Mon. App. 25. 1876. 



1860. Stenionitis echinulata Berk., in Hooker, Fl. Tasm. 2 : 268. 

 1892. Lamproderma listeri Massee, Mon. 97. 



Sporangia loosely clustered, globose, stalked, 0.5-1 mm. in diameter, 

 2-4 mm. tall, shining, with steel-blue or green reflections; wall mem- 



