144 Mycetozoa of North America 



5. fusca on wood, and having short stalks, but there are similar 

 small forms where the stalks are longer, or the spores smaller, or 

 the spores may be brownish with a consequent brownish color to 

 the sporangia. The significant character of typical examples of 

 this variety is the habitat of the plasmodium, and if this is con- 

 firmed by other students, the form well deserves specific rank; as 

 it is now generally recognized that the habitat of the plasmodium 

 is an important character, and particularly so in S. fusca. Var. 

 rufescens (Lister, Mycetozoa 110. 1894) was proposed for forms 

 of S. fusca with rufous gray spores instead of violet gray. The 

 different spore-colors are covered by the description, and as inter- 

 grading shades are often seen, it seems unnecessary to retain the 

 variety. Var. co«^Mew5 (Lister, Mycetozoa 110. 1894. N. Y. 

 B. G. no. 11987, authentic material) has not been reported from 

 North America. It has confluent sporangia without surface nets 

 or columellae, and is close to the genus Amaurochaete, but with 

 spores like those of S. fusca. The history of Stemonitis dictyo- 

 spora Rost. is confusing. Rostafinski mentions it as including 

 the type specimen of Stemonitis trechispora from Venezuela, and 

 he may have meant the name for that species; but he also included 

 a phase of S. fusca with rufous spores (Lister, Mycetozoa ed. 3. 

 133. 1925). Macbride applied the name to a form that appears 

 to be a large phase of 5. fusca. 



2. Stemonitis hyperopta Meylan, Bull. Soc. Vaud. Sc. Nat. 52: 

 97. 1918. (N. Y. B. G. nos. 7455, 7777, 8043, authentic 

 material.) 



Comatricha typhina (Wigg.) Rost. var. heterospora Rex, Proc. Acad. Nat. Sc. 

 Phila. 1893: 367. 1893. 



Plasmodium watery white (Lister). Sporangia in small clus- 

 ters or scattered, short-stalked, broadh' cylindrical, lilaceous 

 brown. Total height 2.5 to 5 mm. Stalk 0.1 to 0.5 mm. high, 

 continued into the slender columella. Capillitium a close net- 

 work of slender, flexuose, brown threads springing from all parts 

 of the columella, the ultimate branchlets forming a more or less 

 complete surface-net in the lower half. Spores pale lilac, 5-6 /x 

 diam., marked with faint spines arranged to form a faintly appear- 

 ing, lax net. 



Var. microspora Lister, Mycetozoa c(i. 3. 134. 1925. (N. Y. B. G. no. 11878, 

 authentic material.) 



