THAXTER. — MONOGRAPH OF THE LABOULBENI ACE^E . 135 



Autoicomyces omithocephalus nov. comb. Plate LXIX, figs. 7 8. 

 Ceratomyces omithocephalus Thaxter. Proc. Am . Acad. Arts and Sei., Vol. XXXV, p. 448. April, 1000. 



Hyaline or becoming more or loss suffused with amber-brownish. Perithecium relatively rather 

 small, the external margin somewhal concave, the inner convex, the four distal cells of the eight external 

 wall-cells rather abruptly enlarged, their external walls much thickened and forming an irregularly rounded 

 crest-like prominence, the distal half of the margin of which becomes abruptly almost horizontal, ter- 

 minating near the base of the beak-like pointed apex, which projects somewhat obliquely from the right 

 side: the external row of wall-cells producing above the fourth cell a large appendage, geniculate at its 

 base, tapering distally where it curves outward, consisting of from ten to twenty cells, the terminal cell 

 rarely bearing one or more slender branches. Receptacle consisting of three superposed cells, the basal 

 one usually opaque, except distally, and continuous with the foot, surmounted by two cells from which 

 arise the perithecium and the appendage. The appendage (usually broken) curved outward and upward, 

 consisting of about ten superposed cells, the upper ones giving rise to few brandies on the inner side, 

 which may be several times branched, the branchlets slender, mostly erect and rather rigid. Spores 

 about 70 X 30 ft. Perithecia 120-160 X 35-45 ft, the crest-like tip 38-45 ft broad, the appendage 120- 

 325 [x. Receptacle 85-120 /*. Appendage, exclusive of branches 140-150 /i. Total length to tip of 

 perithecium 210-290 u. 



On margin of right elytron toward the apex, of Berosus striaius Say. Kittery Point, Maine. 



Occurring rather rarely and always in the same position in company with T. furcatus, T. distortus, 

 and T. humilis, all of which inhabit Berosus in a small pond at the summit of Cutts Island. It is easily 

 separated from the other species by the conformation of the tip, which suggests a beak, subtended by a 

 crest or rounded cockscomb. 



Autoicomyces falciferus nov. comb. Plate LXXI, fig. 19. 

 Ceratomyces jalciferus Thaxter. Proc. Am. Acad. Arts and Sci., Vol. XLI, p. 318. July, 1905. 



Allied to A. ]urcatus, hyaline, the inner margin of the perithecium and the base of the appendage suf- 

 fused with amber-brown, becoming blackish and opaque below the appendage. External margin of the 

 perithecium nearly straight, the inner strongly convex; the pointed tip curved to the base of the large, 

 long, sickle-shaped, external, subterminal perithecial appendage, which consists of about twenty-five to 

 thirty superposed cells, and is curved outward. Receptacle consisting of three superposed cells, sur- 

 mounted by two cells from which the perithecium and antheridial appendage arise; the latter consisting 

 of six or more cells, bearing branches like those of the other allied species on Berosus. Spores 55 X 4 n. 

 Perithecium 125-150 X 55-65 /z, its appendage 435-470 X 22 ft. Receptacle 90-110 X 35 ft. Append- 

 age, without branches, 110-125 fi. Total length to tip of perithecium 250 /«. 



On left inferior margin of abdomen of Berosus sp., Java; Rouyer, No. 1393. 



A species most nearly related to A. fvrcatus, but differing in its small antheridial appendage and very 

 large falcate perithecial appendage, as well as in other points. 



CERATOMYCES Thaxter. 



A revision of the numerous forms which I have published under this name, and the examination 

 of still further material, has led me to the conclusion that at least four distinct types are best separated 

 generically in this assemblage. The largest of these to which the original name Ceratomyces may be 

 applied, includes fifteen described species among which C. viirabilis may be taken as the type. All of 

 these are parasitic on the aquatic genus Tropisicrnus, with the single exception of C. tcrrestris, which al- 

 most certainly should be placed in a genus by itself, its antheridial branchlet (Monograph, Plate XXV, 

 fig. 23) and its general characters being not closely comparable to those of any described genus. Until 

 it can be reexamined in a fresh condition, or until other nearly allied forms are discovered, it seems best, 

 however, to avoid a new generic name by retaining it provisionally in the present connection. 



