EXTRA-AMERICAX LABOULBENIALES. 701 



differs widely in the structure and position of its appendages and peri- 

 thecia. The measurements are taken from larger specimens. 



Dimeromyces Oscinosomalis nov. sp. 



Male individual perfectly hyaline and very thin-walled; consisting 

 of three superposed cells, the basal much larger and somewhat in- 

 flated below; the two others longer than broad, somewhat irregular, 

 of nearly equal length, the terminal appendage distinguished by a 

 slightly darkened septum and constriction, slightly inflated below and 

 tapering distally. Antheridia one, or often two superposed in oblique 

 contact, slightly divergent, the venter and neck not abruptly distin- 

 guished, the latter stout and blunt; a short several-celled secondary 

 appendage rarely formed from the subbasal cell. Receptacle 25 ju. 

 Antheridia IS X 5 fx. 



Female individual. General habit usually subsigmoid. Axis of 

 the receptacle consisting of usually six cells; the base hardly longer 

 than broad, much larger, stout and penetrating the host by a variably 

 developed rhizoid which may be vesicular or taper into a short stout 

 filament, a small, dark primary foot usually distinguishable: the two 

 or three cells above broader than long, somewhat flattened, the two 

 distal ones successively smaller and somewhat rounded; the inflated 

 base of the short tapering primary appendage distinguished by a 

 constriction and dark septum. Secondary appendages usually three, 

 rarely four, long, slender, becoming blackish brown, the distal half 

 curved usually inward away from the perithecium; the distal cell 

 enlarged and abruptly curved, or even uncinulate, becoming irregularly 

 split into an upper and lower half; the basal cell small and short, 

 distinguished from the much larger, often somewhat inflated subbasal 

 cell by a dark septum, the total length nearly twice that of the peri- 

 thecia. Perithecia normally single, arising from the fourth cell of 

 the receptacle, rather stout, slightly bent inward, the stalk obsolete, 

 outer margin strongly convex, tapering slightly to the broad very 

 irregular termination from which the lip-cells, which are all unlike 

 and asymmetrical, project \ariously according to the point of view. 

 Perithecia 50-6.5 X 16-20 fx. Receptacle, exclusive of rhizoid, 35-50 X 

 12-16 /i. Appendages, primary 18 m; secondary, longest, 125 X S n. 

 Total length to tip of perithecium 75-95 n. 



On the inferior surface of the abdomen of Oscinosoma inacqualis 

 T. Beck. No. 21.39, Sarawak, Borneo. 



This species is most nearly related to D. pedalis and D. rhizophorus, 



