418 



THAXTER. MONOGRAPH OF THE LABOULBENIACE/E. 



or bent toward the pore contrasting with the nearly colorless lip-edges below it. Receptacle pale brown 

 or dirty olivaceous, elongate, normal. The insertion-cell nearly horizontal external to cell V, unmodified. 

 The outer basal cell of the appendages giving rise to a single subcorneal brown prominence bearing branches 

 terminally and externally and protruding beyond the inner basal cell, which is indistinguishable from the 

 very numerous branches arising from it in all directions; all the branches hyaline, their basal cells bearing 

 distally several branchlets which may again be branched, the four to eight lower septa dark. Perithelia, 

 average 175 X 44 fi; the spine-like apex 10-12 p.. Total length to tip of perithecium 400^575 it; to 

 insertion-cell 275-400 /«; greatest width 55-70 ji. Appendages about 70 fi. 

 On Dineutesl, Brit. Mus. No. 482, Adelaide River, Australia. 



A comparison of this Australian form with more abundant material of L. Dilantin, makes it appear 

 very doubtful whether the two should be kept distinct, and their separation must be considered merely 

 provisional. I have included under this name the form on Macrogyrus elongatus, represented in fig. 

 12-13, from New Guinea (Sharp Collection No. 1089) in which the conformation at the tip of the peri- 

 thecium is even more unlike that of the typical L. Dineutis (fig. 18), and the appendages are very copiously 

 developed. Yet it is hardly possible without examining more abundant material of all these forms to 

 determine their relationships satisfactorily. 



Laboulbenia fallax Thaxter. Plate, LXVII, figs. 14-15. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 176. Dec, 1899. 

 Perithecium becoming dark dirty olive-brown; the tip blackened, bent outward, the lips hyaline. 

 Receptacle becoming concolorous with the perithecium except the hyaline slender basal cell, the remain- 

 ing cells usually short and stout except cell V, which extends up along the inner margin of the perithecium 

 nearly to its tip, its inner margin continuing the curvature of the tip down to the insertion of the append- 

 ages, so that the perithecium seems at first sight twice its actual size. Insertion-cell unmodified, forming 

 a slight rounded external prominence within which the basal cells of the appendages form an evenly 

 curved base from which arises a single antero-posterior row of branches about twelve in number, their 

 lower cells slightly inflated, hyaline with dark septa, usually twice branched; the ultimate branchlets 

 above the third or fourth septum slender without dark septa, scarcely exceeding the tip of the perithecium. 

 Perithecium 100-120 X 35-40 y. Total length to tip of perithecium 190-325 y; to insertion-cell 120- 

 250 y. Greatest width 85 y. Appendages 50 y. (The larger measurements are from the Amazon speci- 

 mens.) 



On Gyretcs acutangulus Sharp, Brit. Mus. No. 771 (Biologia Coll.), Bugaba, Panama; on Oyretes 

 sp., Brit. Mus. No. 477, Amazon River; on Gyreles sp., Hope Coll. No. 229, Rio de Janeiro. At tips of 

 elytra. 



This species is very clearly distinguished, both from the monstrous development of cell V, and from 

 the crest-like insertion of its appendages. The material is very scanty from all of the localities above 

 mentioned, but there seems to be no considerable variation except in size and depth of suffusion, the 

 latter, which involves the perithecium and the distal portion of the receptacle in most instances, is not 

 shown in fig. 14. In several specimens there are two, or even three, external blackish elevations below 

 the tip of the perithecium, which look like the base of old trichogyncs, and in one young specimen two 

 trichogynes seem actually to have been formed one above the other. 



Laboulbenia rotundata Thaxter. Plate LXVII, fig. 10. 

 Proc. Am. Acad. Arts and Sci., Vol. XLI, p. 317. July, 1905. 

 Perithecium deep brown, except below the tip; broadly rounded, the inner margin of the upper 

 half free above the insertion-cells, and formed by a single long cell extending to the tip, somewhat as in 

 L. fallax, and perhaps representing a marginal extension of the receptacle, as in that species. The tip 

 blunt, with two minute inner tooth-like prominences of unequal size, the larger subtended by a narrow 

 black suffusion, the whole tip more deeply suffused externally. Receptacle straight, elongate, tapering 



