THAXTER. — NEW LABOULBENIACEAE. 405 



On all parts of Scatella stagnalis Fallen. Kittery Point, Maine, and 

 vicinity of Cambridge, Mass., September. Fully developed individuals 

 with the typical structure are uncommon, a majority of the numerous 

 specimens examined having the color dull or paler purplish, the ridges 

 less well defined, without lobulations and with less than a half twist ; the 

 neck and apex hardly, if at all, modified. The same host is infested by 

 an amber-brown form which may prove a mere variety of that above 

 described, being scarcely distinguishable structurally from the less well- 

 marked individuals of this species, the type form of which is, from its 

 remarkable color and the structure of its perithecium, one of the most 

 peculiar members of the genus. 



Stigmatomyces spiralis nov. sp. 



Venter of the perithecium relatively long and slender, flask shaped, or 

 more often but slightly if at all inflated, the granular wall-cells distin- 

 guished by a corresponding number of abrupt, narrow, longitudinal prom- 

 inent ridges, which become minutely roughened, and are spirally twisted 

 so as to describe a full half turn ; the neck concolorous, distinguished by 

 the abruptly elevated and abruptly broadened terminations of the longi- 

 tudinal ridges of the venter, as long as or slightly shorter than the venter, 

 slightly curved or sometimes straight, nearly cylindrical or slightly taper- 

 ing ; the tip slightly but abruptly narrower, relatively short, somewhat 

 asymmetrical ; the apex nearly symmetrical, four papillae being arranged 

 about a somewhat more prominent central projection. Appendage rather 

 short and stout, distinctly broadened in the middle, the stalk-cell stout, 

 the basal cell half as large, or less, and fertile ; the series of six to eight 

 fertile cells above it surmounted by a single antheridium, and distin- 

 guished by slight successive constrictions, broad and much flattened, each 

 bearing a single antheridium, the fifth furnished with a very sharp spine ; 

 the antheridia forming a usually lateral series, their necks becoming 

 strongly curved. Receptacle elongate, slender, becoming brownish or 

 yellowish, the upper cell often more than twice as long as the basal. 

 Spores 22 X 2.0 fi. Perithecium: venter 90-165 X 35-47 fx ; neck 90- 

 160 X 17 ft (the tip 25-30^). Appendage 40-50 /i, the stalk-cell 15 ,/. 

 Receptacle 100-250 X 15 fi. Total length to tip of perithecium 35<i- 

 600 ^ (average 500-550 /x). 



On Hydrina sp., Kittery Point, Maine. Usually on the upper sur- 

 face of the thorax, less ofteu on the legs and elsewhere. 



