THAXTER. — ARGENTINE LABOULBENIALES. 181 



Owing to the difficulties which are met with in determining the 

 exact nature and association of the antheridia in many forms included 

 in the genus it may be assumed that all those in which a two-celled 

 receptacle bears distally a single perithecium on the one hand and a 

 single main appendage on the other, bearing branches on its inner face 

 and terminally, should be sought under Corethromyces, when it pos- 

 sesses no characters which would exclude it from the genus. 



Corethromyces Argentinus nov. sp. 



Perithecium becoming very large, elongate, asymmetrical; the 

 outer margin more prominent; the region of the subbasal wall-cells 

 greatly elongated, usually distinctly suffused with purple-brown, 

 and more or less inflated; or the whole perithecium of nearly the same 

 diameter to the tip; which is well distinguished, blunt-conical, the 

 apex flat, papillate, subtended by a slight elevation: the basal cell- 

 region relatively short and compact, concolorous with the part above, 

 the stalk-cell hyaline, but externally opaque at its base, short and 

 about twice as long as broad. Receptacle small, the basal cell trans- 

 lucent, reddish, broader above than the opaque subbasal cell. Primary 

 appendage opaque below and externally indistinguishable below from 

 the subbasal cell of the receptacle; consisting of three superposed 

 cells, the two lower translucent along their inner margins, their limits 

 barely indicated externally by a slight elevation, the subbasal cell 

 associated with two unequal cells on its inner side; the lower larger 

 than the sul)basal cell itself, inflated, and bearing paired erect branches, 

 which produce branchlets arising near the base only, the two lowest, 

 usually, short, opaque, contrasting, directed obliquely outward; the 

 rest suberect, more or less suffused with purplish or nearly hyaline, 

 coarse, straight or curved toward the perithecium, the tip of which 

 they may exceed when unbroken, the longer branches not numerous 

 (six or more), simple, stout, septate, tapering slightfy to blunt tips: 

 the third, terminal cell of the main axis, very small, mostly translu- 

 cent, bearing distally one or two short branches. Perithecium 160- 

 290X40-55 M, ascigerous part 165-270 m, stalk-cell 40-60X20-30 /x- 

 Spores 40X3.5 /z. Primary axis of appendage 50 ^u: total length to 

 tip of branches, longest 370 ^i; larger branches 8^ in diameter. 

 Receptacle 40 X 8 m- 



On legs and abdomen of Cryptobium sp. Palermo, Nos. 1703-4. 



This species was very common on a dark almost black Cryptobium 

 with yellow legs which frequented the low ground in the park. It is 



