416 



THAXTER. MONOGRAPH OF THE LABOULBENIACEiE. 



Laboulbenia Guerinii Robin. 



Sufficiently abundant material of this species has been examined from a variety of localities including 

 specimens on Gyretes serweus in the Paris Museum collected in Venezuela, if I recollect aright, by Guerin- 

 Meneville, from whom the original material of L. Guerinii was obtained, so that there can be no doubt 

 as to the accuracy of my former reference of the North American forms on Gyretes to this species, despite 

 the fact that, as in the case of L. Rougetii the plant does not agree in all particulars with Robin's account 

 and figures. The species is in general constant in its characters, the most striking departure from the 

 usual form occurring in the specimens of G. cinctus in the Berlin Museum, the locality of which, Rio 

 Janeiro, was doubtful, according to my memoranda. These specimens vary from the type in the consid- 

 erable elongation of cell II, which is quite hyaline and contrasts with a deep brown distal suffusion of cell I. 



Specimens have been examined from the following sources: Hope Collection: No. 227 on Gyretes 

 sp., Mexico: No. 228 on G. cinctus Germ., Brazil. Paris Museum: No. 105 on Gyretes sp., Arauca, 

 Venezuela; Nos. 97 and 104 on G. serireus Lab., "S. America" and Venezuela; No. 107 on G. cinctus 

 Germ., Brazil. British Museum : No. 408 on G. puherulcntus Sharp, Columbia; No. 771 on G. acutangulus 

 Sharp, Bugaba, Panama; No. 770 on G. proximus Sharp, Costa Rica; No. 769 on G. Guatemalensis 

 Reg., Paso Antonio, Guatemala; No. 767 on G. minor Reg., Torola, Mexico ?; on G. Boreandri Chev. 

 Mexico. Sharp Collection: No. 1080 on G. leionatus Duby, Mexico; No. 1078 on G. scriceus Lab., 

 Caraccas, Venezuela, U. S. National Museum; on Gyretes sp., Texas. Berlin Museum: No. 800 on 

 G. cinctus Germ., Rio Janeiro ?; No. 801 on G. dorsalis Brulle, Brazil; No. 802 on G. immarginatus, 

 Mexico; No. 803 on G. pruinosus Sharp, Columbia. 



Laboulbenia drepanalis Thaxter. Plate LXVII, figs. 5-6. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 173. Dec, 1899. 



Perithecium smoky olive, the inner half or less usually much paler, the upper three fourths free, fal- 

 cate; the inner margin concave, the tip undifferentiated, the lip-edges forming a small hyaline rounded 

 abruptly distinguished papilla. Receptacle rather short, concolorous with perithecium; cell I paler or 

 hyaline with a basal blackish suffusion; cell V large, growing upward above the oblique insertion-cell 

 which is thus pushed out free from the perithecium together with the basal cells of the appendages. In- 

 sertion-cell small, unmodified. Basal cells of the appendages closely united, and finally indistinguish- 

 able from one another, forming a prominent rounded outgrowth which gives rise to about six or eight 

 branches, their dark basal septa of variable diameter only remaining, as a rule; the basal cells of the 

 branches are distally inflated, and bear several branchlets externally and terminally, the basal cells of 

 the branchlets mostly similar to those of the primary branches and similarly branched, the ultimate 

 branchlets closely septate, the septa dark. Perithecia, Panama specimens 100 X 40 u, Amazon 140 

 X 35 /i. Total length to tip of perithecium, Panama 210 u, Amazon 275 ft; to insertion-cell, Panama 

 130 p., Amazon 140 u. 



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

 sp., Brit. Mus. No. 477, Amazon. On mid-elytron. 



This species is distinguished from others of the same section by its falcate perithecium and small 

 prominent insertion region. Specimens from Panama differ from the Amazon material, which is taken 

 as the type (fig. 5), in their smaller size and darker color; but are not otherwise essentially distinguished. 

 As in so many of the aquatic forms, the appendages are either badly broken or wholly wanting in the 

 specimens examined. 



Laboulbenia heterocheila Thaxter. Plate LXIV, fig. 16. 



Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 179. Dec, 1899. 

 Perithecium olive-brown, united to cell IV nearly to its base, rather short, inflated below, tapering 

 distally, the tip not abruptly differentiated, blackened below, the four lip-cells all differently modified : 

 of the two inner lips one produces an erect rather slender brown finger-like terminal outgrowth, the other 



