100 THE MYXOMYCETES 



The form of the sporangium in the only species is very variable, but 

 in typical cases is vasiform, the peridial wall at the apex introverted. 

 The capillitium is like that of Timadoche, except for the presence of 

 the "straight tubes" emphasized in the original description. These 

 are very remarkable and at once diagnostic. They take origin in the 

 sporangial wall and pass across to the "columella"; but at the de- 

 hiscence of the sporangium, in typical cases, they remain attached at 

 the points of origin, projecting as stout spine-like processes. The 

 formation of the capillitium has been studied by Bisby (1914). 



Physarella oblonga {Berk. & Curt.) Morg. 



Jour. Cin. Soc. Nat. Hist. 19 : 7. 1896. 

 PI. X, Figs. 223, 224, 225. 



1873. Trichamphora oblonga Berk. & Curt., Grev. 2 : 66. 



1873. Physarum rufibasis Berk. & Br., Jour. Linn. Soc. 14 : 85. 



1875. Chondrioderma injlatum Rost., Mon. 425. 



1876. Tilmadoche oblonga (Berk. & Curt.) Rost., Mon. App. 13. 

 1876. Tilmadoche Mans Rost., Mon. App. 14. 



1882. Physarella mirabilis Peck, Bull. Torrey Bot. CI. 9 : 61. 

 1888. Tilmadoche minuta Berl., in Sacc, Syll. Fung. 7 : 361. 

 1892. Physarum Mans (Rost.) Massee, Mon. 296. 



Sporangia scattered or gregarious, typically cup-shaped or sub- 

 infundibuliform, stipitate, erect or cernuous, but varying through low 

 salver-shaped cups, to irregular applanate and sessile masses; peridium 

 thin but firm, tawny, roughened by numerous yellowish calcareous 

 scales, at length ruptured above and often reflexed in the form of 

 petal-like segments from which project upwards the spine-like trabe- 

 cules of the capillitium; stipe when present long, terete, red, arising 

 from a scant hypothallus and extended within the sporangium to meet 

 the tubular pseudocolumella; capillitium of delicate violaceous threads 

 seldom branched or united, radiating from the columella with few 

 calcareous nodular expansions, but supported by stout, yellow, cal- 

 careous trabecules, running parallel to the capillitial threads, long ad- 

 herent to the sporangial wall; spores nearly smooth, globose, violet- 

 brown, 7-8 ix. 



Not uncommon, usually in wet places. New York to South Dakota, 

 Washington, and Louisiana, Nicaragua, British Guiana, Brazil; re- 

 ported also from Ceylon, Java, Japan, Africa and the tropics generally. 

 Rare in Europe. 



Whether the form described from Portugal as Physarella lusitanica 

 Torrend is a distinct species is not certain. It is small, stalked, some- 

 times subglobose and ovoid without pseudocolumella. 



