220 A MonograpJi of the Myiognstres. 



variable in length, blackish or rnfmis, wrinkled longitudinally, 

 equal or slightly attenuated upwards, expanding at the base 

 into a rudimentary hypothallus; coluinella hemispherical or 

 depressed, covered with the inner darlc hrmun wrinkled skin, 

 lacunose, the cavities filled with amorphous masses of lime; 

 capillitium copious, threads springing from the columella, 2 — 3 /x 

 thick, almost equal, dividing in a dichotomous manner, and 

 becoming attached to the inner wall of the sporangium, the 

 branches often connected laterally, and often more or less 

 studded with very minute granules of lime, varying from colour- 

 less, through pale brown lo dingy violet ; spores globose, dirty 

 brownish-purple, minutely warted, 1 — 1 3 ju, diameter. 



a. gemoinum. Stem blackish or brown, as long or longer 

 than the height of the sporangium. 



/3. suhsessile. Stem short, almost or altogether concealed in 

 the umbilicus of the sporangium. Sporangia solitary or more 

 or less confluent. 



y. nigrum. An abnormal form without lime, hence the 

 sporangium from the first blackish. Stem short. 



Didymium farinaccum, Rost., Mon., p. 154, figs, 128, 171, 

 174; Cooke, Myx. Brit., p. 31, figs. 128, 171, 174; Sacc, Syll., 

 1039 ; Schroeter, p. 121 ; Raunk., Myx. Dan., p. 89. 



Didymium lohatum, Ft. (specimen named by Fries, in Herb. 

 Berk., n. 10753). 



Exdcc. — Jack, Leiner u. Sitzenb., 424 ; Cooke, Fung. Brit., 

 Ed. II., 521; Fuckel, Fung. Khen., 1461; Klotzsch., (Rab.) 

 Herb. Myc, 138; Rab., Fung. Eur., 369. 



On wood, bark, leaves, living moss, &c. 



Britain (Chislehurst, Kew, Carlisle, Scarboro', Durham, Lin- 

 lithgow, Appin) ; Sweden ; Germany ; Bavaria ; France ; United 

 States ; S. W. Australia ; Benin Islands. 



Sporangia b — 1 mm. across, sometimes lobed, a character 

 which gave origin to the spurious species D. lohatum; some- 

 times two or several sporangia coalesce, the stems remaining 

 distinct. The stem varies considerably in length, even in the 

 same group, thus showing the small amount of value to be 

 attached to Rostafinski's forms; in some specimens the stem 



