MONOGRAPH OF THE LABOULBENIACE^E. 



317 



by its perithccium, the broad apex of which is peculiarly flattened and bent strongly outward. 

 It is comparatively rare, and does not appear to vary to any extent. 



Laboulbenia contorta Thaxter. Plate XV, figs. 1-5. ■ 



Proc. Am. Acad. Arts and Sci. Vol. XXVII, p. 42. 



More or less suffused with reddish brown. Perithccium becoming suffused with blackish 

 In-own, sometimes quite opaque ; outwardly inflated, its tip turned strongly outward, the lip-cells 

 forming a very broad and characteristic hatchet-shaped apex, its edge becoming almost vertical, 

 the whole perithecium somewhat twisted and bent toward the appendages, its axis crossing theirs 

 in mature individuals about at right angles. Appendages arising from two basal cells, the outer 

 large, elongate, giving rise to a single appendage once branched or simple; the inner half as 

 large, producing usually two simple branches, each usually producing a single pair of antheridia. 

 Receptacle rather elongate, abruptly expanded above cell II ; cells I— II forming a long, nearly 

 cylindrical, stout stalk, rather abruptly contracted at the foot ; cells IV-V elongated and twisted 

 so that the appendages and their insertion cell are often carried across at right angles to the 

 axis of the perithecium. Spores, 75 x 5 /x. Perithecia, 150-180 x 60-75 ljl. Total length to tip 

 of perithecium, 330-400 ii ; greatest width, 90-100/*. Appendages about 300 /x. 



On Platynus extensicollis Say, and P. affinis Kirby, Maine to Virginia. 



This curious species is very constant in form, and is abundantly distinct from any other 

 species of t\\c flag ellata type. It is at once distinguished by the hatchet-shaped apex of its peri- 

 thecium and the peculiar distortion which grows more marked in older specimens. The species 

 is a rare one, and is found almost invariably on the inferior lateral face of the prothorax of its 

 host, usually on the right side. 



Laboulbenia gibberosa Thaxter. Plate XV, figs. 6-8. 



Proc. Am. Acad. Arts and Sci. Vol. XXVII, p. 43. 



More or less faintly tinged with reddish brown. Perithecium short, stout, expanding slightly 

 from the base to a conspicuous external hunch just below its broad, almost truncate apex. 

 Appendages arising from a large outer and a very small inner basal cell ; simple or bearing two 

 to three branches, always above the sub-basal cell, constricted at the septa, the segments becom- 

 ing slightly inflated, the tips usually curved and tapering: the disk of insertion small and thick. 

 Receptacle elongate, strongly twisted above cell II, the twist continued by cells IV and V, which 

 are much elongated, and carry the appendages out at right angles to the axis of the perithecium. 

 Spores, 50 x 4.5 ii. Appendages, 180 /*. Perithecia, 125 x 50 ii. Total length to tip of peri- 

 thecium, 500-550 fx. 



On Platynus extensicollis, New England. 



A number of specimens of this rare and singular species show that the twisted receptacle is 

 a constant character, which is sometimes carried to such an extreme that the ordinary direction 

 of the appendages is reversed ; the elongation and curvature of cells IV and V bending them 

 toward the base of the receptacle. The species is large and unusually elongate, growing on the 



