70 THE MYXOMYCETES 



the capillitium, in some of the Nicaragua collections the lime is more 

 uniformly distributed through the capillitium, and accordingly the 

 nucleus is not conspicuous, its place being taken by two or three nodes 

 plainly larger than the others. The peculiar brown metallic luster of the 

 peridial wall and the strongly developed calcareous patches with which 

 the peridium is covered are fairly constant features. RostafLnski called 

 it a tilmadoche, with which group it might easily be placed. The 

 capillitium is, however, distinctly netted. 



The name Didymium columbinum Berk. & Curt, was never pub- 

 lished, although fragmentary remains under this name exist in both 

 the Berkeley and the Curtis herbaria. Rostafinski based his Tilma- 

 doche on Berkeley's specimen, and Miss Lister, who has examined it, 

 believes it is the same as Tilmadoche compacta Wingate. This is con- 

 firmed by Sturgis, after an examination of the material in the Curtis 

 herbarium. Physarum columbinum Pers. is universally recognized as 

 having been applied to Lamproderma columbinum; Physarum colum- 

 binum Somm. may have been the same thing although Fries regards it 

 as distinct from the form he cites as columbinum. His description, 

 however, strongly suggests a lamproderma. But whatever they may 

 be, the name cannot again be used. Massee's names are cited on the 

 authority of Lister. One or the other may eventually have to be 

 adopted. For the present, wingatense will serve to designate the species 

 as it occurs in North America. 



North and South America and West Indies; Africa, southern Asia, 

 Malay Peninsula, Japan. 



42. Physarum didermoides {Ach.) Rost. 



Mon. 97. 1875. 

 PL V, Figs. 88, 89, 90. 



1801. Spumaria ? didermoides Acharius, in Pers. Syn. Fung. Add. xxix. 



1803. Diderma oblongum Schum., Enum. PI. Saell. 2 : 197. 



1832. Physarum atrum Schw., Trans. Am. Phil. Soc, II. 4 : 257. 



1832. Spumaria licheniformis Schw., Trans. Am. Phil. Soc. II. 4 : 261. 



1849. Claustria didermoides (Ach.) Fr., Summ. Veg. Scand. 2 : 451. 



1850. Didymium congestum Berk. & Br., Ann. Mag. Nat. Hist. 2 ser. 5 : 365. 

 1875. Physarum lividum Rost., Mon. 95. 



1875. Physarum lividum Rost., var. licheniforme Rost., Mon. 96. 



1882. Physarum cinereum (Batsch) Pers. var. ovoideum Sacc, Michelia 2 : 334. 



Sporangia crowded, ovoid or cylindric, 0.4-0.6 mm. broad, stipitate 

 or sessile, blue-gray, often capped with white; stipe variable in length 

 and structure, where well developed pure white, often flattened, ex- 

 panded and diaphanous, connate with others through the irregular, 

 reticulate or sheet-like hypothallus; columella none; capillitium ample, 



