CRIBRARIA 169 



A very minute but well-marked species discovered by Dr. Rex 

 in Wissahickon Park, near Philadelphia, otherwise very rare. 

 Lister, however, reports it from England. In minuteness to be 

 compared with C. winutissima, from which its color instantly 

 distinguishes it. Dr. Rex reports the plasmodium as " violet 

 black." All our specimens are on very rotten wood, basswood, 

 Tilia americana. 



Pennsylvania, Illinois. 



12. CRIBRARIA PURPUREA Schrad. 



1797. Cribraria purpiirea Schrad., Nov. Gen. Pt., p. 8. 



Sporangia gregarious, large, I mm. in diameter, dark purple, 

 erect, stipitate, depressed-globose ; stipe concolorous, furrowed, 

 about twice the diameter of the sporangium in length, with a 

 distinct hypothallus ; calyculus persistent, less than half the 

 sporangium, obscurely ribbed, marked by concentric plications, 

 the nlargin toothed ; the net poorly differentiated, the meshes 

 irregular in form and size, as are also the flat, unthickened nodes, 

 the threads pale, free ends short and not numerous ; spore-mass 

 purple ; spores by transmitted light, pale or colorless, 5-6 /*, 

 smooth. 



Rare. Found on rotten coniferous wood in deep forests. 

 Easily recognized by its large size and uniform purple color. 

 To the next species it offers a general resemblance, but has 

 larger sporangia and an entirely different net. The plasmo- 

 dium just before the formation of the fruit is scarlet. 



Maine, New York, Pennsylvania, Ontario. 



13. CRIBRARIA ELEGANS Berk, and Curt. 



1873. Cribraria elegans Berk, and Curt., Grev., II., p. 67. 



Sporangia gregarious, erect or nodding, small, .4-. 5 mm., 

 bright purple, stipitate ; stipe long, slender, tapering upward, 

 almost black, arising from a scanty hypothallus ; calyculus about 

 half the sporangium, finely ribbed, covered especially above 

 with small purple granules, the margin toothed or perforate; 

 net well developed, the meshes small, polygonal, the threads 



