diderma] physajraceae 105 



Rost. Mon., App. p. 18 (1876) ; Mass. I.e., 210. C. similans 

 Rost. I.e., p. 20; Mass. I.e., 209. C. crustaceum Berlese in 

 Sacc. Syll., vii. 373 (1888); Mass. I.e., 215. C . frustulosum- 

 Pat. in Bull. Herb. Boiss., iii. 61 (1895)? 



PI. 85. — a. sporangia seated on a stout hypothallus (Poland) ; b. capillitium and 

 spores with fragment of sporangium-wall ; c. spore. 



Rostafinski describes the spores of Chondrioderma globosum as " pale 

 violet, 8 /jl diam.," but the specimen from Warsaw in the Strassburg 

 herbarium marked with this name in his handwriting (referred to 

 Rost. Mon., p. 180) has dark rough spores, 11 to 13 /t diam. Whether 

 Rostafinski had seen other specimens corresponding with his descrip- 

 tion remains uncertain ; such forms have been occasionally met with 

 in the United States (Macbr. I.e., 98), and appear to he on the border 

 line between D. globosum and D. spumarioides. The type of C. affine 

 Rost., also from Warsaw, is similar in all respects to the Warsaw gathering 

 of D. globosum, above referred to. Specimens of the present species 

 gathered on the Swiss Alps show interesting transitional forms ; 

 on the one hand they may approach D. spumarioides in having spores 

 only 10 /J. diam., and on the other they may resemble D. niveum in 

 the pale orange tint of the floor of the sporangia ; the latter are often 

 elongated to form short plasmodiocarps. (See Meylan in Bull. Soc. 

 Vaud., xliv. 289, 1908.) 



Hob. On dead leaves and twigs. — Holt, Norfolk (B.M. 2394) ; 

 France (B.M. 2398) ; Strassburg (B.M. 1289) ; Sweden (B.M. 2395) ; 

 Poland (Strassb. Herb.) ; Italy (B.M. 525) ; Switzerland (B.M. 2396); 

 British Columbia (B.M. 2397) ; Kansas (B.M. 2399) ; Colorado (B.M. 

 2400) ; Iowa (B.M. 816) ; New Hampshire (B.M. 1288). 



6. D. niveum Macbr. N. Am. Slime-Moulds, 100 (1899). 

 Plasmodium white. Sporangia crowded, subglobose, or 

 hemispherical, sessile, 0-7 to 1*5 mm. diam., smooth, white, 

 sometimes seated on a white or dull yellow hypothallus ; 

 sporangium- wall of two layers, the outer densely charged 

 with white lime-granules, separating from the more persistent 

 inner layer, which is membranous and often iridescent above, 

 cartilaginous and orange below. Columella broad, convex, 

 or hemispherical, orange or buff. Capillitium of branching 

 and anastomosing rather stout purple threads with pale 

 extremities, sometimes intermixed with more delicate threads, 

 and often beaded with wart-like thickenings. Spores purple- 

 brown, minutely spinulose, 9 to 13 /x diam. — Chondrioderma 

 niveum Rost. Mon., p. 170 (1875); Mass. Mon., 206; Lister 

 Mycetozoa, 80. C. pkysaroides Rost. I.e. ; Mass. I.e., 214. 

 C. albescens Mass. I.e., 209 (1892). Diderma albescens Phill. 

 in Grev., v. 114 (1877). 



Subsp. 1. — Lyallii Lister : sporangia subglobose or obovoid, 

 white or pale ochraceous, 1 to 1*5 mm. diam., sessile or on 

 short stout furrowed whitish stalks arising from a well 

 developed hypothallus ; columella hemispherical or clavate, 

 ochraceous ; spores purple-brown, spinose, 11 to 15 ^ diam. — 



