242 



THAXTER. 



MONOGRAPH OF THE LABOULBENIACEiE. 



Of D. Africanus, illustrated in my Monograph, I have examined additional material from Cape 

 Coast Castle, Africa, on Pachyteles, in the Hope Collection No. 287. 



Dimeromyces minutissimus Thaxter. Plate XXIX, figs. 0-9. 

 Proc. Am. Acad. Arts and Sci., Vol. XLI, p. 304. July, 190.5. 



Male indiridual. Receptacle consisting of three cells, the basal externally suffused with blackish 

 brown, and projecting beneath the base of the antheridium; the subbasal giving rise to the solitary anthe- 

 ridium; while the distal is separated by a blackened septum from a two-celled erect rigid distally spinose 

 appendage. Venter of antheridium small, tapering gradually to the stout outcurved neck. Total length, 

 including foot, 32 fi. Antheridium 16 X 5 u. 



Female individual. Receptacle very irregularly formed, externally blackened above the large foot; 

 consisting of several irregularly superposed cells, the subbasal giving rise to a two-celled prominence 

 subtending a blackish tapering appendage, which projects at right angles to the colorless primary append- 

 age; the latter two-celled, distinguished by a blackish septum, and often subtended by a similar append- 

 age from the same (distal) cell of the receptacle. The single perithecium rather short and broad, tapering 

 slightly to the more or less distinctly differentiated somewhat truncate tip. Length to tip of perithecium 

 50 fi. Longest appendage 40-50 fi. Perithecium 34 X 10 fi. 



On the inferior surface of the rhabdites of Labia minor Burm., Cambridge, Mass. 



This and the preceding species may prove merely variations of the same form due to the differences 

 in their position of growth, and are only provisionally separated. M . Labia is much less common than 

 the present species and has only been seen on the elytra. M. minutissimus occurs not uncommonly on 

 the rhabdites, but is very difficult to find and to remove, from its minute size, dark color and appressed 

 habit of growth. Both species are most nearly allied to M. Forficulw, although abundantly distinct 

 from it. 



Dimeromyces Labile Thaxter. Plate XXIX, figs. 1-5. 

 Proc. Am. Acad. Arts and Sci., Vol. LXI, p. 303. July, 1905. 



Male individual. Receptacle consisting normally of three superposed cells, the basal projecting 

 laterally to form the base of the lowest antheridium, bearing distally a two-celled appendage distinguished 

 by a basal blackish septum; the two upper cells of the receptacle producing two, rarely three, antheridia: 

 the latter short and stout, the efferent region containing the several tubes rather abruptly distinguished 

 from the venter, as well as from the common efferent tube, which curves outward somewhat abruptly. 

 Total length to tip of appendage, including foot, 50 fi. Appendage 25 fi. Antheridium 16-18 X 6-7 u. 



Female individual. Subhyaline, or straw-colored, consisting of an irregular axis of three or four 

 superposed cells, terminated by a simple, usually two-celled, appendage distinguished by a blackish 

 septum; the subbasal cell bearing a broad blunt bicellular upcurved appendage or protrusion, which 

 subtends either the single perithecium, or a several-celled appendage similar to the primary one. Peri- 

 thecium solitary, colorless, somewhat elongate, tapering but slightly to the more or less abruptly 

 distinguished rather broad somewhat flattened tip. Total length of tip of perithecium 65-75 fi. 

 Perithecium 50-60 X 12 fx. Spores about 18 X 12 fi. 



On the elytra of Labia minor Burm., Cambridge, Mass. 



As has been already mentioned, this species is very closely related to D. minutissimus of which it 

 may prove a mere variety due to its position of growth. The material is not abundant, but the differ- 

 ences indicated in the figures and descriptions appear to be constant, even the greater number of antheridia 

 in the male individuals. The host is a small Forficula common in refuse, especially in the Fresh Pond 

 region. 



Dimeromyces Forficula Thaxter. Plate XXVIII, figs. 9-11. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXVIII, p. 9. June, 1902. 



Male individual. Receptacle consisting of three superposed cells, the upper distinguished by a 



