108 THE MYXOMYCETES 



but not numerous, crystals; hypothallus none; columella none; capil- 

 litium of much branched, violaceous threads combined to form a 

 rather dense net which bears numerous, peculiar, rounded vesicles, 

 yellowish in color, 30-50 /jl in diameter; spores minutely warted, 7-9 /i, 

 pale violaceous brown. Plasmodium greenish yellow. 



The defining characteristics here are the curious supplementary 

 vesicles which are visible as brown knots under a hand lens. These are 

 attached to and penetrated by the neighboring capillitial threads, 

 withal warted like a spore. They suggest the curious spore-like but 

 giant cells found in the stipes of some arcyrias. Rostafinski gives them 

 abundant consideration, illustrating them on pi. 9, figs. 166 and 180, 

 of the Monograph, although in the explanation of the plate he has 

 strangely confused the species with Didymium crustaceum Fr. Under 

 Didymium serpula, Fries may refer to the present species, although 

 there is nothing in his description to determine the fact. The same 

 thing may be said of the description and figures of Batsch. Rostafinski, 

 in the Monograph, seems to have been satisfied as to the identity of 

 Batsch's materials: in the Appendix, he writes D. serpula, but gives 

 no reason. 



Rare. New York, Pennsylvania (?), Iowa; Europe. 



5. Didymium anomalum Sturgis 



Colo. Coll. Pub. Sc. Ser. 12 : 444. 1913. 



Plasmodiocarp gray, very thin, effused, 2-10 mm. long; wall single, 

 membranous, hyaline or yellowish with rather scanty deposits of small, 

 stellately crystalline or amorphous lime; columella none; capillitium 

 consisting entirely of straight, membranous, tubular columns, extend- 

 ing from the base to the upper wall of the plasmodiocarp, 7-22 /* thick 

 and usually containing small crystalline masses of lime; spores bright 

 violet-brown, minutely and irregularly spinulose, 10.5-11.5 ju. 



The original description gives the length of the plasmodiocarps as 

 2-10 cm. In our material, from Dr. Sturgis, and evidently a portion 

 of the type collection, there are two plasmodiocarps 3-4 mm. in length, 

 and a couple of smaller ones, less than 1 mm. Presumably "cm." 

 was written in error. The description of the thickness, as "less than 

 1 mm." is misleading. They are exceedingly thin, perhaps 0.1-0.2 mm. 

 Nevertheless the curious peg-like capillitial columns may readily be 

 seen under a binocular. 



Massee transferred Rostafinski's Chondrioderma anomalum to Di- 

 dymium as D. anomalum. Lister thinks these names may be synonyms 

 of D. squamulosum. Whatever they may represent, Sturgis' name 

 would seem to be preoccupied, and may have to be changed. The 



