PHYSARUM 77 



globuliferum; much smaller, however, and in every way different. 

 The generic characters are mixed, and the species has been accordingly 

 variously referred. The lower part of the peridium is sometimes 

 persistent after the dehiscence, and so far reminds of Craterium. But 

 this character is not constant, and even at best the persisting part is 

 very small, not greater than in P. melleum, for example. On the 

 other hand, the capillitium in some sporangia is strongly calcareous, 

 reminds of Badhainia, but in most sporangia the Physarum characters 

 are sufficiently clear. 



In the Kew Herbarium, it is said, are two American specimens 

 under one label, "Didymium pusillum." One specimen is a didymium 

 indeed, but, as it appears, D. proximum Berk., already described. 

 The other is a physarum. It is proposed in Mycetozoa, 2nd ed., to 

 use the combination thus set free, as if applied by the original author 

 to the second specimen, not didymium, and to make the new combina- 

 tion date from 1873 and so take precedence of the binomial applied in 

 1881 by Cooke and Balfour here retained by the law of priority. 



35. Physarum maculatum Macbr. 



Plate XIV., Figs. 6, 6 a, 6 b. 



1893. Bull. Lab. Nat. Hist. loiva, II., p. 383. 



1899. Physarum maculatum Macbr., N. A. S., p. 47. 



1911. Physarum tenerum Rex., Lister, Mycetozoa, p. 52, in part. 



Sporangia scattered or gregarious, very small, .3-.4 mm., dull gray, 

 thin-walled, dotted with minute, white calcareous granules, stipitate; 

 stipe long, about 2 mm., stout, attenuated upward, striate longitu- 

 dinally or wrinkled, filled with irregular yellow masses of lime and 

 accordingly bright yellow in color ; columella none ; capillitium form- 

 ing a dense net, with comparatively small yellow nodular thicken- 

 ings; spores globose, purplish, each minutely papillose and displaying 

 several scattered spots occasioned by local development of the papillae ; 

 diameter of the spores 9-10 fx. 



This species was set up for the reception of certain material col- 

 lected by Professor Shimek, in 1892, in Nicaragua. It remains so far 

 unique. The small globose sporangium mounted upon a long up- 

 wardly tapering stipe, .5 mm. thick below, but narrowed at the ex- 



