TILVXTER. — ARGENTINE LABOULBENIALES. 1G3 



the fertile branches may be very irrej^ular. Although perhaps a dozen 

 perithecia may be formed on a single individual, many are apt to be 

 broken and but few ever mature. The species is most nearly allied to 

 H. siviilis and //. Ilomalotae from both of which it is distinguished by 

 the character of its primary appendage and by the proliferous habit 

 of its fertile branches. The genus of the host has been determined 

 by Dr. Fenyes. 



MONOICOMYCES INFUSCATUS Speg. 



Receptacle very small, the basal cell becoming more or less suffused 

 with smoky brown, broader than long, the hyaline subbasal cell 

 hardly distinguishable. Primary appendage stiff rigid upcurved, 

 black externally from its base upward, simple or producing a single 

 branch above its subbasal cell which may be similarly blackened. 

 Fertile branches usually producing a single perithecium and antheri- 

 dium, more rarely two by proliferation, suffused, especially externally, 

 with blackish olive-brown; the two distal tiers forming a well defined 

 rounded enlargement, terminated by two erect blackened rigid 

 appressed hyaline-tipped appendages. Perithecium hyaline or faintly 

 olivaceous, slightly asymmetrical, subfusiform, the tip hardly dis- 

 tinguished, the apex blunt, the narrower basal cell region not dis- 

 tinguished, the basal cells relatively large, the stalk-cell short and 

 broad, not abruptly distinguished below the basal cell-region. Spores, 

 in perithecium, about 20X2.7 /jl. Perithecia 90X2G /z, the stalk-cell 

 18X12 yu. Antheridium 45-70 fj., its appendages 45-70 fj.. Primary 

 appendage with its branches, 110 ^t. Receptacle 18X12 ^u. 



On the abdomen of Xantholinus Andinus Fauv., No. 1689, Palermo, 

 No. 1988, Llavallol. 



A small and apparently rare species, very closely allied to M. 

 nigresccns and distinguished especially by its rigid black primary 

 appendage. 



Mimeomyces nov. gen. 



Receptacle consisting of two superposed cells, the upper bearing 

 terminally the single appendage and the stalk-cell of the single peri- 

 thecium. Appendage consisting of a basal cell and several cells 

 superposed above it, the lower bearing single free compound antheridia 

 on the inner side, the upper bearing sterile branches. The antheridia 

 consisting of a group of apparently six similar antheridial cells and 

 originating directly from the slightly swollen extremity of a short 



