122 Mycetozoa of North America 



tributed deposits of lime in the form of stellate or angular 

 crystals. Columella a thin ridge or plate extending along the 

 plasmodiocarp from the base upward to nearly the top, and filled 

 with angular lime-granules. Capillitium a dense network of 

 pale, slender threads, among which are numerous vesicular bodies 

 several times the size of the spores, paler in color, and spinulose. 

 Spores dark purple-gray, 10-12 /x diam., marked with coarse, 

 scattered spines, which are often confluent to form short ridges. 



Type locality: Kansas. 



Habitat: On dead leaves. 



Distribution: *Iowa, Kansas. 



Illustration: Martin & Brooks, Trans. Am. Mic. Soc. 57: 

 320, figs. 1-5. 



This species has been found in Kansas repeatedly over several 

 years by Mr. Travis E. Brooks, the junior author, and he has 

 also found it in Iowa. It is interesting, not only because of the 

 large vesicular bodies in the capillitium, similar to those in D. 

 complanatum, but because of the thin, plate-like columellae ex- 

 tending longitudinally throughout the plasmodiocarps from the 

 bases nearly to the tops. In the type collection, the surface lime 

 is in the form of crystalline, angular nodules. In other gather- 

 ings, the stellate crystals, characteristic of the genus Didymium, 

 are present. 



8. Didymium Clavus (Alb. & Schw.) Rabenh. Deutsch. Krypt. 

 Fl. 1: 280. 1844. 



Physarum Clavus Alb. & Schw. Consp. Fung. 96. 1805. 



Plasmodium gray or colorless (Lister). Total height 0.4 to 

 1 mm. Sporangia scattered, disc-shaped, often centrally de- 

 pressed, 0.7 to 1 mm. diam., 0.2 mm. thick, stalked, erect, 

 grayish white; sporangial wall membranous, more or less spotted 

 with brown, and with superficial clusters of stellate crystals of 

 lime above, thickened and brown at the base. Stalk cylindrical, 

 longitudinally striate, brown or black. Columella represented 

 only by the thickened discoid base of the sporangium. Capilli- 

 tium profuse, consisting of sparingly branched colorless or purple- 

 brown threads. Spores pale violet-brown, almost smooth, 5-8 ju 

 diam. 



Type locality: Germany. 



Habitat: On dead leaves, twigs, and wood. 



