1 88 THE NORTH AMERICAN SLIME-MOULDS 



2. LACHNOBOLUS OCCIDENTALIS Macbr. 



PLATE II., Figs. 2, 2 a, 2 b. 



1885. Lachnobolus incarnatus (Alb. and Schw.) Macbr., Bull. Lab. Nat. 

 Hist. Iowa, II., p. 126. 



Sporangia scattered or crowded upon a hypothallus more or 

 less distinct, globose or ellipsoidal, short-stipitate, varying some- 

 what in color, at first rosy or flesh-colored, later brownish or 

 ochraceous ; the peridium exceedingly thin, pellucid, meally, 

 evanescent above, persisting as a shallow cup below ; capil- 

 litium inelastic, rather closely netted of threads variable in 

 thickness, marked by frequent thickenings or expansions, every- 

 where warted, attached to the peridial wall ; spores in mass 

 flesh-colored, under the lens colorless, smooth, globose, 7.5-9 AI. 



This delicate and elegant little species appears to be not 

 uncommon, but is probably generally passed over as an Arcyria, 

 which it superficially resembles. When newly formed, the 

 sporangia have a peculiar 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 spherical on dis- 

 tinct short stipes ; when crowded, the shape is of course less 

 definite. The capillitium never expands as in Arcyria, but, 

 exposed 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 dis- 

 tributed as L. incarnatus (Alb. and Schw.) Schroet. A careful 

 study of all the descriptions of European forms and comparison 

 of many specimens leads us to believe that we have here to do 

 with a type presenting constant peculiarities. We have in 

 America nothing to correspond with the figures of Schweinitz, 

 Berkeley, or Lister. In the American gatherings the sporangia 

 are uniformly regular, globose, very generally short-stipitate, 

 more or less closely gregarious, never superimposed, or heaped 

 as shown in Berkeley's figure, for instance, Ann. and Mag. Nat. 

 Hist., IV., xvii., PL ix., Fig. 2. The plasmodium of our species is 



