242 A Monograph of the ' Myxogastres. 



of lime, as is also the orbicular, depressed, pale columella ; capil- 

 litium colourless, threads very slender, combined into a dense 

 irregular net; spores globose, brownish-lilac, minutely ivarted, 

 8 11 JM diameter. 



Didymium eximium, Peck, in 31st Rep. N. York State Mus., 

 p. 41 ; Sacc., Syll., n. 1314. 



Exsicc. Ellis and Everhart, N. Amer. Fung., Ser. II., 2089. 

 (Authentic specimen from author in Hb., Kew.) 



On dead leaves, herbaceous stems, &c. U. States. 



Scattered or gregarious, from 1 1'5 mm. high, stem twice 

 or more the length of the sporangium. Threads of capillitium 

 often more or less dilated at the angles, and rarely with a 

 slightly thickened interstitial portion, which does not however 

 contain lime. 



Didymium flavicomum, Mass. (figs. 76 78). 



Sporangium depresso-globose, minutely umbilicate below, 

 pab 'yellow, at first frosted with a few scattered crystals of lime ; 

 stem elongated, slender, erect or slightly curved near the apex, 

 snbequal or attenuated upwards, yellowish-rufous, often darker 

 at the base, which expands into a minute hypothallus, longi- 

 tudinally wrinkled and containing amorphous granules of lime ; 

 columella absent; capillitium pale yellow, threads variously 

 combined to form a rather dense net, dilated at the nodes, which 

 are without a trace of lime ; spores almost colourless, very 

 minutely veii'uculose, 9 10 p diameter. 



Physarum flavicomum, Berk., Hook. Journ. Bot., vol. iv., 

 p. 66; Sacc., Syll., n. 1193 (in part). 



Physarum Berkeleyi, Host., Mon., p. 105. 



(Type in Herb. Berk., n. 10,782.) 



On decorticated wood. Australia (Swan River). 



Gregarious, 2'5 3 mm. high, stem slender, three to four 

 times as long as the sporangium. The present very distinct 

 species has been hopelessly confused by Rostafinski and by 

 Berlese in Saccardo's SyUoge, and the mistakes committed by 

 both can be traced to the modern pernicious system of paying 

 attention to books rather than specimens, always a mistake, and 



