710 THAXTER. 



each bearing a branch distally and externally which, in the cells above 

 the seventh or eighth, is replaced by a single cell bearing one or more 

 antheridia; the branches, of which there are about seven, all fertile, 

 except that from the subbasal cell which is sometimes sterile, consist- 

 ing of from one to three cells forming a short divergent axis, and bearing 

 each from one to several straight concoloroiis antheridia distally and 

 inwardly; the terminal and sometimes the subterminal cells pro- 

 ducing externally a vertical series of from two or three to five out- 

 curved, closely set, short, rather stout, brownish, simple branchlets, 

 which are usually slightly geniculate near the middle: the branches 

 replaced in the cells of the main axis above the eighth by a single small 

 cell, from which one or more antheridia arise directly. Stalk-cell of 

 the perithecium terminal, long and stout, nearly uniform, except that 

 the diameter is somewhat less at the base, and distally, where the basal 

 cell region is rather abruptly distinguished; the latter rich dark red 

 amber-brown, the basal cells surrounding the lower third of the asci- 

 gerous cavity, their external margins prominent and very thick- 

 walled; the rest of the perithecium concolorous or somewhat darker; 

 the two lower tiers of wall-cells marked by more or less distinct 

 transverse lines; the whole slightly curved, somewhat inflated below, 

 tapering distally to its more or less clearly indicated junction with the 

 paler tip and apex, which taper to a bluntly rounded termination, 

 with hardly distinguished lips; the tip giving rise, from almost its 

 whole inner surface, to a slightly divergent and curved, rather slender, 

 concolorous appendage, which subtends the apex. Spores small and 

 numerous, perhaps about 15 X 2 /x. Perithecia, including basal cell 

 region, 150 X 58 m; stalk-cell 508X28^. Receptacle 35X28/^. 

 Appendage about 275-350 n, the axis X 12 ju, the branches, larger, 

 about 40 fjL. Total length to tip of perithecium 690 /x. 



On the inferior surface of the abdomen of a species of Dmpsis, near 

 the tip. No. 2330, Gambia River, West Africa, Dr. Wolbach. 



A very distinct species allied to R. denophorus , at once distinguished 

 by its spinose perithecium and circinate or helicoid appendage. 



Rhizomyces confusus nov. sp. 



Rhizomyces crispahis Thaxter, pro parte. ]\Iem. Am. Acad. Arts 

 and Sci. Vol. XIII, No. 6, p. 323, Plate LII, figs. 19 and 21. 



^\hen this species was first described, the material of R. crispahis 

 was somewhat scanty, but the examination of a large series has shown 



