TILMADOCHE 6 1 



4. TILMADOCHE COMPACTA Wingate. 



PLATE XVI., Figs. 3, 3 a, 



1876. Tilmadoche columbina (B. and C.) Rost., Man, App., p. 13. (?) 



1889. Tilmadoche compact a Wingate, Proc. Acad. Nat. Sci., p. 48. 



1892. Lepidoderma stcllatum Massee, Man., p. 52, teste Lister. 



1894. Physarum compactum Lister, Mycctozoa, p. 45. 



1896. Physarum compactum (Wingate), Morgan, Jour. Cin. Soc., p. 91. 



Sporangia gregarious, or somewhat crowded, erect or cernu- 

 ous, stipitate, gray or brownish gray, globose; peridium thin, 

 metallic brown or bronze in color, splitting at maturity in flori- 

 f orm manner into six to twelve segments ; stipe white or yel- 

 lowish white, often shading to black or fuscous below, rather 

 long, tapering upward ; hypothallus none ; columella none ; 

 capillitium extremely delicate, white or colorless, radiating from 

 a central lime mass or nucleus, and with ordinary nodules small 

 and few, fusiform ; spore-mass brown ; spores by transmitted 

 light, violet brown, delicately warted, 7-8 //.. 



This species is well marked by several characteristics ; the 

 brilliant wall of the peridium, white-flecked and laciniate, the 

 delicate Didymium-\\ke capillitium, running from centre to 

 peridium, and especially the peculiar aggregation of lime at the 

 center of the sporangium, like nothing else except a similar 

 structure found in Physarum nucleatum Rex. The variations 

 affect the stipe and the distribution of the capillitial lime. 

 Some eastern specimens show stipes melanopodous, black be- 

 low ; specimens from Ohio and Nicaragua show stipes milk 

 white throughout. As to 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 lustre of 

 the peridial wall, and the strongly developed calcareous patches 

 with which the peridium is covered are constant features. That 

 this is the Didymium columbinum Berk., or T. columbina (Berk.) 

 Rost., is very doubtful ; the specific name given by Wingate is 

 therefore adopted. The capillitium is extremely delicate, and 



