338 



MONOGRAM OF TIIE LABOULBENIACEiE. 



much smaller size of L. palmella, its wholly opaque and short receptacle, straight, short-necked, 

 proportionately stouter perithecium, large hoof-like hase, together with the absence of furca- 

 tion in the main axis of the two lateral branches of its inner appendage, afford sufficient 

 specific differences. The antheridia appear to be represented by flask-shaped bodies borne 

 on short hyaline branches near the tips of the branchlets of the inner appendages. The 

 trichogynes are well developed and more or less copiously branched. The very large amount 

 of material examined indicates that this species is subject to little variation in form and is rela- 

 tively constant in size. 



Laboulbenia Pheropsophi Thaxter. Plate XX, figs. 13-15. 



Proc. Am. Acad. Arts and Sci. Vol. XXVIII, p. 170. 



Perithecium becoming suffused with blackish brown, straight, the two upper thirds free from 

 the receptacle, rather slender, the outer margin curving abruptly inward to the base of the 

 prominent tip, which is itself bent slightly outward, its base deeply suffused. Outer appendage 

 slightly divergent, somewhat exceeding the perithecium, composed of usually five or six super- 

 posed cells, somewhat longer than broad, each of which gives rise externally from its upper half 

 to a single simple short branch, tapering distally, slightly constricted near the base, where it 

 is divided by a blackened septum : insertion-cell rather broad, black, and considerably exceeded 

 externally by the free upper surface of cell IV. Inner appendage smaller and similar or once 

 to twice sub-dichotomously branched above its basal cell, the lower septa blackened. Recep- 

 tacle normal, cell II usually hyaline, the rest becoming suffused with olive-brown. Spores, 

 75 x 4.5 p. Perithecia, 150 X 50 p. External appendage, 100-150 (j,, its branches about 50 /x 

 long. Total length to tip of perithecium, 250-500 p. 



On Pheropsophus cequinoctialis Linn., and several undetermined species from South America. 

 On P. marginatum Dej. var. ? from Zanzibar, and Pheropsophus sp. indet., Liberia, Africa (O. F. 

 Cook). 



This form appears to be common on species of Pheropsophus from South America occurring 

 on all parts of the host. In general form it is much like some varieties of L. elongata, but is 

 at once separable by its appendages, which are peculiar both in form and method of branching. 

 Among the hosts examined in the collection of the Museum of Comparative Zoology one 

 labelled " P. marginatus Dej., var (?) " from Zanzibar, was found to bear a small number of 

 specimens of a Laboulbenia apparently identical with this species except that the antheridia 

 were long with slender necks and borne terminally in pairs on short branches. All the speci- 

 mens are, however, immature, so that it is impossible to determine whether it possesses other 

 distinctive characters. The types vary somewhat in the relative development of the inner 

 appendage, and the form is often more slender than is represented by the figure. Additional 

 material on Pheropsophus from Liberia collected by Professor Cook has since been obtained, 

 and although the difference above noted in the antheridia is observable in these also they do 

 not seem to be specifically distinct from the South American types, which they otherwise 

 resemble in all respects. 



