CONTRIBUTIONS FROM THE CRYPTOGAMIC LABORATORY OF 

 HARVARD UNIVERSITY. — XLII. 



PRELIMINARY DIAGNOSES OF NEW SPECIES OF 

 LABOULBENIACE^. — 2. 



By Roland Thaxter. 



Received March 19, 1900 ; Presented April 11, 1900. 



Dimorphomyces Myrmedoniae nov. sp. 



Male individual tinged with smoky brown, relatively small, similar to 

 those of the other species, except that the neck of the antheridium is pro- 

 portionately much shorter, its base inflated, its distal portion short and 

 attenuated ; the distal cell of the receptacle large, distally very thick- 

 walled, the thickened portion undergoing a gelatinous degeneration. 

 Total length to tip of antheridium, including foot, 65 fx, to tip of sterile 

 portion 40 /x. Antheridium 38 /a long, the venter 25X14 /x. 



Female individual relatively large, tinged with smoky brown, the 

 sterile part of the receptacle terminated by a blunt distal cell, subtended 

 by a blackened septum, the distal portion of which is thick walled and 

 often swollen or disappearing through gelatinous degeneration; the fer- 

 tile portion resembling that of the other species in general structure but 

 developed almost at right angles to the axis of the sterile part on one 

 side only, as in D. Thleoporae, very long and nearly isodiametric throuofh- 

 out ; the perithecia from two to five in number and the appendages from 

 three to six, alternating as a rule, the two series diverging slightly from 

 opposite sides, the subtending cells relatively large and slightly oblique 

 in reference to the marginal portion, so that their size appears to be 

 greater when viewed on one side than on the other. Perithecium 

 rather long and slender, nearly straight, stouter in small individuals and 

 somewhat inflated ; the tip blunt or nearly truncate ; tinged with smoky 

 brown, borne on a short divergent stalk-cell (hardly visible), from which 

 it bends abruptly upward. Appendages relatively large, consisting of 

 two superposed cells constricted at the septa, the basal one longer, distally 

 more deeply suffused, the upper distally suffused and modified like the 



