288 A Monogra2'>h of the Myxogastres. 



Didymium sqi/amnlosum, which differs in the large, white 

 columella. Distinguished from sessile forms of Fhysarum leu- 

 copliaeum, by the coarser capillitium furnished with numerous 

 large nodes, and the slightly larger and more coarsely warted 



spores. 



(Rostafinski's Synonyms.) 



Didymium Icucopiis, Link, Diss., 2, p. 42 (1809). 



Fhysaimm hullatum, Link, Diss., 2, p. 42 (1809); Ditmar, 



t. 22. 

 Physaritm cdhopunctatum, Link, Herb. 

 JDidymiiLm leucojms, Fr., S. M., iii., 121 (1829); Engl. FL, v., 



p. 313; Cke., Hdbk., n. 1127. 

 Fhysarttm o-amentaceum, Fr., in litt. ad Wein (1836). 



Physarum leucophaeum, Fr. (figs. 63 — 66 and 96). 



Sporangia subglobose, usually a little depressed below, stipitate 

 or sessile, wall thin, with irregular, white, innate patches of 

 lime, dehiscing irregularly ; stem usually longer than the spor- 

 angium, erect, slightly attenuated upwards, longitudinally rugu- 

 lose, brown, paler above, passing into a dark hypothallus ; capil- 

 litium dense, colourless, anastomosing very irregularly, threads 

 thill, often flattened at the angles ivhich rarely contain lime; 

 spores globose, dingy lilac, minutely warted, 8 — 10 fx diameter. 



/. fasciculatum. Stems confluent. 



/. sessile. Stem very short or entirely absent, sporangia 

 scattered or confluent, regular or sometimes elongated and 

 anastomosing. 



Physarum lcicco2)haeicm, Fr., Symb, Gast., p. 24; Rost., Mon., 

 p. 113, figs. 77, 78, and 89; Cooke, Myx. Brit., p. 15, figs. 77 

 78, and 89; Sacc, Syll., n. 1192; Schroeter, 129; Raunk., Myx. 

 Dan., p. 75. 



Didymium pruinosum, B. and C, Cuban Fungi, n. 530. 

 (Type in Herb. Berk.) 



On leaves, twigs, bark, moss, &c. Britain (Queen's Cottage 

 grounds, Kew ; Hampstead, Bristol, Deal, Scarboro', Carlisle, 



