XEAV DIMORPHOMYCETEAE. 259 



On the elytra of Eustilbus apicalis Slip., Agua Caliente, Guatemala. 

 (Kellerman). 



Among the few specimens of this species which are available only 

 two males and a single female are uninjured, so that more copious 

 material will probably necessitate some modification of the above 

 description. The species is so well defined, however, that I have felt 

 it safe to include it in the present enumeration. Its claw-like foot, 

 transversely ridged perithecium, the form of which is otherwise 

 characteristic, the characters of the secondary appendage with its 

 greatly elongated basal cell, as well as the structure of the slender 

 male with its relatively large, distally and externally hunched anther- 

 idium serve clearly to separate it from other known forms. 



Dimeromyces eximius nov. sp. 



Male individual relatively large. Receptacle nearly opaque, except 

 the basal and the lower portion of the subbasal cell; consisting of 

 about five superposed cells, the lower two much flattened, terminated 

 by an undifferentiated appendage consisting of two cells; the lower 

 much larger, the upper shorter and narrower, slightly translucent, 

 especially its flattish distal margin. The successive cells of the 

 receptacle above the basal, producing an anterior series of unicellular 

 branches, or protrusions, from each of which may arise one or more 

 antheridia or appendages or both combined; the appendages stiff, 

 simple, faintly brownish, rather closely septate, the septa darker and 

 slightly constricted, slightly divergent; the antheridia sessile, rather 

 short and stout, the three regions very clearly distinguished; the neck 

 short, stout, distally rounded and slightly broader, curved slightly 

 inward; the venter large, faintly brownish; the middle efferent 

 region contrasting red-brown: the insertion blackened. Receptacle, 

 including large foot, 58 X 15 /x. Primary appendage 22 X 12)u; 

 secondary 130 ^c or more, X 8 /jl. Antheridia 38-44 X \-i fx. Total 

 length to tip of appendage 82 yu. 



Female individual similar in structure to the male, the secondary 

 appendages more numerous and elongate, curved upward and inward, 

 distinctly brownish, the septa darker, with a slight constriction. 

 Primary appendage indistinguishable, the axis quite opaque above the 

 basal cell. Perithecia one or two, lying at the left, like the antheridia, 

 while the secondary appendages, except two or three of the lowest, 

 lie at the right: the stalk very short, nearly hyaline, abruptly bent; 



