404 



THAXTER. 



MONOGRAPH OF THE LABOULBENIACE^E. 



This species, though closely allied to L. Pachytelis, of which it might at first sight appear to be an 

 abnormal development, was found on several specimens of this small Arizona Pachyteles, always in the 

 same general position and in no case varying from the type form illustrated in Fig. 10. The antheridial 

 branch occupies a median position, the two antheridia diverging slightly on either side, and apparently 

 arising from a very small stalk-cell. Its abnormally bent habit, its pointed and hunched perithecium, 

 and its inflated primary outer appendage, consisting of two similar cells, basal and subbasal, distinguish 

 it clearly from L. punetulata, L. Ozcence and L. Parliytclis which are its nearest allies. 



Laboulbenia Texana Thaxter. 

 The type form of this striking species has not again been observed since the original material was 

 obtained on species of Brachiwus from Texas and Guatemala; but a number of forms on Bracliinvs 

 which approach it perhaps too closely for specific separation, have been distinguished as varieties. The 

 type forms of these varieties, though occurring in widely separated localities, are absolutely identical, 

 and show scarcely any variation and the same is true of the form previously described as L. rostellata, indi- 

 viduals from Florida and from Montevideo being identical. The series of varieties as a whole, however, 

 shows certain gradations between extreme forms, and the character of the appendages, although subject 

 to peculiar variations in luxuriance of development is, on the whole, so constant that I have concluded 

 to retain varietal designations in all cases. This disposition of the forms must be, nevertheless, con- 

 sidered as provisional; and further study of material from the La Plata region, as yet unexamined, 

 may indicate that a revision of this opinion is desirable. The present species is so closely allied to L. 

 Pachytelis, which also occurs on an allied host, that it would be difficult to distinguish a variety like 

 retusa from some of its many variations. The varieties illustrated in the accompanying figures which have 

 been greatly reduced (X 150) as compared with the other figures of the plate, may be distinguished as 

 follows : 



Var. rostellata Thaxter. Plate LXIII, fig. 5. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXVIII, p. 55. June, 1902. L. c , Vol. XXXV, p. 199. Dec, 1899, 



as L. rostellata n. s. 



Perithecium about one half free, becoming more or less deeply suffused with blackish brown, relatively 

 small, narrow and curved toward the appendages, distally monstrously developed, bulging terminally 

 and externally to form a rounded prominence from the inner side of which the tip projects inward in the 

 form of a blunt pointed, blackened outgrowth, the hyaline contrasting apex of which is bent slightly up- 

 ward. Receptacle more or less suffused, sometimes deeply colored with blackish brown, cells I and II 

 paler, slender, of nearly equal width, cell II longer; cells IV and V very broad, carrying out the insertion- 

 cell free from the receptacle so that it becomes oblique or even vertical and lateral. Outer and inner 

 appendages similar, bent away from the perithecium, their bases overlapping; consisting of a series of 

 superposed cells which are successively smaller from below up, each bearing distally and externally a 

 short tapering branch; all the branches brown, the subbasal septa blackened, all simple except the lower 

 branch of the outer appendage which bears two or three short branehlets; the basal cell of the inner append- 

 age bears a short antheridial branch from its inner side; the outer appendage somewhat longer than the 

 inner, the superposed cells usually eight in number. Perithecia 140-190 X 40-50 /«. Total length to 

 tip of perithecium 400-550 \r, to insertion-cell 270-450 \i. Appendages, 140-170 fx. Tip of perithecium, 

 including outgrowth, 50-60 \i. 



On Brochinus lateralis Dej., Hope Coll. No. 246, "North America"; on Brachvnus sp., Eustis, 

 Florida, October; on B. gcniculatus Dej., Berlin Museum No. 992, Montevideo, Uruguay. At base of 

 anterior legs. 



Specimens from the localities mentioned are remarkably constant in character, the subbasal and 

 basal cells of the receptacle, however, usually forming a stalk which is more abruptly differentiated 

 from the distal portion than is indicated by the individual represented in fig. 5. 



