472 W. C. Sturgis — Type-Spechnens of Myxomycetes. 



it is accompanied by no figures, and, so far as I know, there is no 

 authentic specimen in existence. Under these circumstances cer- 

 tainty is out of the question, and it seems to me unwise in principle 

 to supersede a generally recognized name of many years' standing 

 and referring to a well-known form, by a name to which no certainty 

 can be attached. The original description of the shape, the habit, 

 and the color of the capillitium of P. cmsp>itosum, Schw., seems, as 

 noted by Lister, to apply quite as well to J-*. virescens, Ditm., as to 

 P. citrhiellmn, Pk., if not better. 



Phtsarum flavidum, Pk. {Didymium flavidum, Pk.), Rep. 

 XXVIII, p. 54, 1875, and Rep. XXXI, p. 55, 1878. The type-speci- 

 men of this species is unfortunately immature, nevertheless the fol- 

 lowing characters can be determined from it. 



Sporangia scattered, dull yellow, subglobose, sessile or shortly 

 stipitatc, 0.5-0.6"^™ in diameter, seated upon or rising from a thin, 

 membranous hypothallus. Stalk, when present, robust, membran- 

 ous, brownish-yello.w. Wall double ; the outer, pale yellowish-grey, 

 membranous above and beset with scattered aggregations of yellow 

 lime-granules, thicker and persistent below ; the inner, very delicate 

 and colorless, widely separated from the outer wall. Capillitium 

 composed of delicate, colorless threads with rounded lime-knots of 

 medium size of a white or pale straw coloi'. Spores pale violet, 

 (black in the mass), minutely spinulose, variable in size, but averag- 

 ing 9.7-11.2/x in diametei". 



The almost sessile character of the sporangia, the wide sjDace 

 separating the inner from the outer wall, the fact that the spores 

 form a shrunken, indurated mass, the pale color of the spores when 

 separated, and their variable size, are all indications of immaturity. 

 Fortunately, however, there is little choice in deciding where the 

 species properly belongs. It is evidently an immature specimen of 

 Physarum citrinellum, Pk. ( Cratefium citrinellum, List.) 



FuLiGO ocHRACEA, Pk. {Licea orchracea, Pk.), Rep. XXVIII, 

 p. 55, 1875, and Rep. XXXI, p. 56, 1878. The type specimen of this 

 species is fairly abundant and in good condition. Listei-'s description 

 (1. c, p. 67) fits the specimen so exacth^ that it is unnecessary to 

 attempt to add to it. Macbride makes Peck's name a synon^j-m of 

 Fxdiyo miiscorum, A. & S., a name apparently overlooked by Lister. 

 The description and figures given of their species by Albertini and 

 Schweinitz (Consp. Fung., p. 86, Tab. VII, fi.g. 1) are exceptionally 

 good and, as stated by Macbride, they seem referable to J^. ochracea, 

 Pk. On the other hand, in the absence of the type-specimen, we 



