246 THE NORTH AMERICAN SLIME-MOULDS 



warted or roughened, with few expansions or inflations; spores in 

 mass pale yellow, under the lens colorless, almost smooth, 7-8 fi. 



This singular little species is remarkable chiefly in the habitat it 

 affects, — fallen chestnut burs. On these almost universal, but on 

 nothing else, except on the fallen catkins of the same species. Regard- 

 ed by Mr. Lister as A. cinerea, from which it differs constantly in 

 form, in capillitium more open and with larger threads, 4-5 /i in 

 diameter as well as in its unique habitat, and yellowish color. 



Distribution coterminous with that of Castanea dentata Bork- 

 hausen, — eastern half of the United States. 



2. Lachnobolus occidentalis Macbr. 



Plate II., Figs. 2, 2 a, 2 i ; 4 and 4 a. 



1885. LacJinobolus incarnatus (Alb. & Schw.) Macbr., Bull. Lab. Nat. 

 Hist. loiva. II., p. 126. 



Sporangia scattered or crowded upon a hypothallus more or less 

 distinct, globose or ellipsoidal, short-stipitate, varying somewhat in 

 color, at first rosy or flesh-colored, later brownish or ochraceous; 

 the peridium exceedingly thin, pellucid, mealy, evanescent above, per- 

 sisting as a shallow cup below ; capillitium inelastic, rather closely net- 

 ted of threads variable in thickness, marked by frequent thickenings 

 or expansions, everywhere warted, attached to the peridial walls, 

 spores in mass flesh-colored, under the lens colorless, smooth, globose, 

 7.5-9 /.. 



This delicate and elegant little species appears to be not uncommon, 

 but is probably generally passed over as an Arcyria, which it super- 

 ficially resembles. When newly formed, the sporangia have a pecul- 

 iar rosy or flesh-colored metallic tint, which is all their own. Within 

 a short time this color passes, and most of the material comes from the 

 field brownish or ochraceous in color. Typical sporangia are spheri- 

 cal on distinct short stipes; when crowded, the shape is of course 

 less definite. The capillitium never expands as in Arcyria, but, ex- 

 posed by the vanishing upper wall, remains a spherical mass resting 

 upon the shallow cup-like base of the peridium. 



This species has been in the United States generally distributed as 

 L. incarnatus (Alb. & Schw.) Schroet. A careful study of all de- 



