THAXTER. — NEW LABOULBENIACEAE. 21 



Corethromyces longicaulis nov. sp. 



Receptacle abuormally developed, very small, the basal and subbasal 

 cells arising almost side by side immediately above the foot ; the basal 

 cell long and narrow, strongly curved so as to become concave externally, 

 its wall very thick, the cavity becoming almost obliterated ; the distal 

 half nearly horizontal, slightly bulging and becoming wholly deep black 

 brown, except along its upper (in position) margin which is transparent 

 yellowish and closely applied to the lower surface of the basal cell of the 

 appendage, beyond which it hardly projects externally and which thus 

 appears to arise from it ; the subbasal cell larger, nearly hyaline exter- 

 nally, convex, bulging below, with a more or less distinct constriction 

 below its slightly enlarged upper portion, which gives rise distally to the 

 broad stalk-cell of the perithecium and sublaterally to that of the append- 

 age. The appendage much reduced, nearly hyaline, consisting of three 

 superposed cells; the basal (stalk-cell) squarish or rounded, the lower 

 half or less of its inner margin connected with the subbasal cell of the 

 receptacle, its subbasal cell smaller, bearing usually a single short anther- 

 idial branchlet ; the upper cell still smaller, often hardly distinguishable, 

 bearincr one or two short antheridial branchlets and a short sterile termi- 

 nal branch. Antheridia terminal, one to three in a series. Stalk-cell of 

 the perithecium relatively very large, often curved, usually as large as 

 the other parts of the plant combined, brown, slightly constricted at its 

 insertion, nearly cylindrical, slightly and gradually broader toward and 

 below the basal cells, which are relatively small and, barely separate the 

 cavity of the perithecium from that of the stalk-cell ; body of the peri- 

 thecium concolorous with the stalk-cell, slightly inflated, tapering distally 

 almost symmetrically to the blunt tip, which is somewhat asymmetrical 

 from the slightly greater prominence of one of the lip-cells ; the series of 

 wall-cells strongly spiral, completing as a rule somewhat more than one 

 whole turn. Spores 30 X 3 /i. Perithecia G5 X 20 fi, the stalk-cell 90- 

 110 X 12 fi. Receptacle 25 /x. Appendage 30-40 /x. Total length to 

 tip of perithecium, average 200 fx. 



On StiUcus angularis Lee, at the base of the head on the upper side ; 

 Arlington, Mass., June. Sometimes associated on the same host with 

 G. Stilici Thaxt. 



ACOMPSOMYCES Thaxter. 



The past season has yielded two additional species of this well-marked 

 genus, the material of which is sufliciently abundant to determine with 

 greater accuracy than was formerly possible its distinctive characters. 



