708 THAXTER. 



curved and tapering slightly; the wall-cell regions not distinguished, 

 the lips hyaline, slightly vesicular; the outer wall-cell of the apex 

 developing, at the right, a slightly divergent, strongly outcurved, 

 slender, elongate appendage, brown with hyaline tip, the base darker, 

 partly concealing the blunt apex of the perithecium, marked by a 

 depression nearly opposite the pore on the inner side, which may be 

 subtended by a more or less well defined tooth-like projection. Spores 

 about 25 X 2 /i. Perithecia 52-75 X 16-18 /i; its appendage 75- 

 140 X 4-5 M- Appendage 50-80 fx. Receptacle 10-14 X 12-14 fx. 

 Total length to tip of perithecium 90-145 fx. 



On the inferior surface of the abdomen of the right side of species of 

 Ilythea. No. 2043 (Type) and No. 1856, Clarkstown and Balaclava, 

 Jamaica, W. I. No. 2524, St. George, Grenada (Brues), No. 2515, 

 Bocas del Toro, Panama (Rorer). 



This striking species which may be regarded as the type of the genus, 

 since it illustrates its highest development, is clearly distinguished 

 from all other American forms which are known to me, by the row 

 of characteristic outer branchlets from the axis of the appendage. 

 Individuals from different sources show some variation. Nos. 2524 

 and 1856 differ from the others in that the appendage is usually 

 shorter with fewer cells; the perithecium and its base decidedly 

 smaller, while the appendage, or trigger-organ, is much longer, and 

 lacks the tooth-like projection which is always present at the base in 

 the shorter type. These differences, however, do not appear suffi- 

 cient for even varietal separation. 



Ilytheomyces mauubriolatus nov. sp. 



Basal cell of the receptacle small, indistinguishable from the foot 

 which thus appears relatively larger, its upper edge, only, hyaline; the 

 subbasal cell broader than long, its outer margin strongly convex, 

 lying above the basal cell, and beside the base of the appendage; 

 which is also in contact with the basal cell of both the receptacle and 

 the appendage. Axis of the latter blackish brown, distally curved 

 or recurved, the basal and subbasal cells similar and distinguished by 

 a slight indentation of the inner margin: the upper and lower margins 

 of the subbasal cell free; the well defined androphorous cell arising 

 from it distally, on the inner side, subhyaline, and bearing two large, 

 stout, brown, nearly straight, hyaline-tipped antheridia side by side; 

 one of the latter on the left being sometimes replaced by a short. 



