276 A Monograph of the Myocogastres. 



to the typical form, but Rostafinski has given as forms of this 

 species a heterogeneous collection, varying considerably in habit, 

 colour, and size of spores, but all agreeing in having a colu- 

 mella; how many of these forms are British I do not know, 

 fi. chrysopus, which appears to be the same as Physarum citri- 

 num, Schum., has been collected in Yorkshire, and a specimen 

 probably corresponding to y. aurantiacum has been met with 

 at Neatishead. 



The following are Rostafinski's forms. 



Var. a. genuinum. Sporangium yellow or greenish-yellow, 

 mm. wide, stem yellow ; spores 7 8 \j. diameter ; granules of 

 lime yellow. This variety is the one described above as the 

 type form. 



ft. chrysopus. Sporangium 1 mm. diameter, with the stem 

 golden-yellow; spores 10 /* diameter; granules of lime golden- 

 yellow. 



y. aurantiacum. Sporangia | mm. diameter; stem brown; 

 sporefi orange, 11 ft diameter; granules of lime brown. 



8. rujipcs. Sporangium yellow or orange, sometimes iridescent ; 

 stem orange-red ; granules of lime yellowish. 



e. compactum. Plasmodiocarp veinlike, creeping, short, yellow 

 or golden ; columella absent, disappearing with the stem. 



Didymium melleum,, B. and C., given as a synonym of the 

 present species by Rostafinski, although a Physarum, is quite 

 distinct, as shown by an examination of the type specimen in 

 the Berkeley collection in the Kew Herbarium. 



(Rostafinski's Synonyms.) 



Physarum titrinum, Schum., SaelL, i., 436 (1803). 



Pkysarum aurantiacum, ft. rufipes, A. and S., Cons., 262 (1805). 



Physarum vcmwosum, Link, Herb. 



Physarum compactum, Ehr., Syl. Ber., p. 21 (1818). 



Physarum SchumacJicri, Spr., Syst., iv., p. 528 (1827). 



Diderma citrinum, Fr., S. M., iii., 100 (1829); Cooke, Hdbk., 



n. 1107. 



Diderma rujipcs, Fr., S. M., iii., 101. 

 Diderma compactum^ Wallr., Herb. 



