Didymium. 221 



is three times as long as the height of the sporangium, in 

 others so short as not to project beyond the umbilicus or 

 depression at the base of the sporangium. The threads of the 

 capillitium are often flexuous. The columella is at first dusky 

 owing to being covered with the dark inner skin of the spor- 

 angium, but in old plants this pellicle frequently disappears, 

 leaving a white mass of lime, hence the columella appears 

 white. 



(Rostafinski's Synonyms.) 



Sphaerocephalus niger, Hall, t. 1, f. 2 (1742). 



Trickia, Hall, No. 2160, t. 48, f. 2 (1768). ' 



Mucor sphaerocephalus, Batsch., p. 157 (1783). 



Clafhrus sphaerocephalus, Rehl..(1786). 



Trichia glolosa, Vill., Fl. Dauph., 1061 (1789). 



Eeticularia hemispherica, Bull., t. 446, f. 1 (1791). 



Trichia compressa, Trent, p. 229 (1797). 



Trichia sphaerica, Trent, p. 230 (1797). 



Trichia depressa, Trent, p. 231 (1797). 



Physarum melanospermum, Pers. Disp., p. 8 (1797). 



Didymium farinaceum, Schrad., t. 3, f. 6 (1797) ; Engl. Flor., 



v., 313; Cooke, Hdbk., No. 1123; Fung. Brit., Ed. II., 521. 

 Trichia sphaerocephala, Sow., t. 240 (1799). 

 Trichia farinacea, Poir., Encycl., viii., 53. 

 Physarum farinaceum, Pers. Syn., 174 (1801). 

 Physarum cinerascens, Schum. Saell., 1426 (1803). 

 Physarum depressum, Schum. Saell., 1439 (1803). 

 Physarum globosum, Schum. Saell., 1442 (1803). 

 Physarum oxyacantJiae, Schum. Saell., 1427 (1803). 

 Physarum cinereum, multis ? 

 Physarum clavus, Link, Diss., i., 27 (1809). 

 Physarum sinuosum, Link, Diss., i., 27 (1809). 

 Physarum capitatum, Link, Diss., i., 27 (1809). 

 Diderma muscicola, Link, Diss., i., 27 (1809). 

 Didymium capitatum, Link, Diss., iii., 27 (1816). 

 Didymium lobatum, Nees, f. 104 (1817); Cooke, Hdbk., No. 



1129. 



