THAXTER. — 



MONOGRAPH OF THE LABOULIiKM ACK.K. 



327 



This species is doubtfully separated from S. obfimns on account, of the very different eon forma I ion 

 of the tip of the perithecium, which, as the material in either case occurred in the same position on the 

 host, can hardly be due to position of growth. Their retention as distinct species is, however, only pro- 

 visional. 



CERAIOMYCES Thaxter. 



Proc. Am. Acad. Arts and Sci., Vol. XXXVI, p. 410. March, 1901. 



Structure of the peritheciuni as in Laboulbenia, its stalk-cell united to the free base of the free stalk- 

 cell of the appendage, which bears a well differentiated insertion-cell terminally, from the end of which 

 arc home autheridial branches, their successive cells producing terminally either successive secondary 

 branchlets, or antheridia or both. Receptacle two-celled. 



This genus is in some respects very similar to Laboulbenia, with species of which it might be confused 

 on superficial examination. It differs in possessing an appendage, the stalk-cell of which is free from the 

 stalk-cell of the perithecium. The main appendage, moreover, consists of but two superposed cells 

 terminated by an insertion-cell which does not necessarily give rise to outer and inner branches. As in 

 species of DiTneromyces and Rliizomyces, the two forms herewith illustrated differ in their relation to the 

 host; C. DaJtlii, which grows on a soft-bodied fly, being characterized by a copiously branched rhizoid 

 that enters the body cavity, whereas G. Selena' is attached by the usual blackened foot. 



Ceraiomyces Dahlii Thaxter. Plate XLIII, figs. 3-6. 

 Proc. Am. Acad. Arts and Sri., Vol. XXXVI, p. 410. March, 1901. 



Perithecium large, blackish brown, with an olive shade, becoming opaque, usually slightly curved, 

 tapering gradually to the slender undifferentiated tip; the anterior lip-cells forming two appressed hyaline- 

 tipped finger-like projections; the base very broad, translucent, dull brownish, bulging conspicuously 

 below the venter, especially on the left side; the stalk-cell small, nearly isodiametric, united on its inner 

 side to the base of the stalk-cell of the appendage. The latter free, though often in contact with the 

 base of the perithecium, dull blackish olive, outwardly inflated, narrower terminally where it bears the 

 characteristically differentiated basal cell of the appendage, which becomes almost opaque and is some- 

 what flask- or bottle-shaped with a rounded extremity, from which, typically, two divergent branches 

 arise which in turn may branch one to three times subdichotomously ; the long slender flask-shaped 

 antheridia borne, one to two together, distally from the successive cells. The basal cell of the receptacle 

 nearly spherical, penetrating the host by a long filament which is slender except for an enlargement im- 

 mediately below the integument of the host, simple at first but becoming more or less copiously branched ; 

 the upper cell very large and elongate. Spores about 30 X 3 p.. Perithecium 275-310 X 55-60 ft; the 

 base, including the stalk-cell, 68-72 X 58-68 [x. Appendage 75-85 ti (the basal cell 18 X 12 /<), the 

 stalk-cell 40-45 X 18-22 /«. Receptacle 175-240 X 35 [x (the basal cell 20-22 /i). Total length to tip 

 of perithecium 400-675 li, average 550 li. 



On various parts of a small flower fly. Ralum, New r Pomerania. Berlin Museum, Nos. 1283 and 

 1298. 



This species is conspicuous from its large size and dark color, and growing, as it often does, projecting 

 forward from the head of its host, was at first mistaken for an antenna. The many peculiarities of this 

 fine species need hardly be pointed out, and are clearly indicated by the accompanying figures. In all 

 the specimens the black insertion-cell gives rise to two antheridia] branches. The species has been named 

 alter Dr. Dahl of the Berlin Museum, from whose collections of Papuan Diptera so many interesting 

 Laboulbeniales were obtained. 



Ceraiomyces Selin.e Thaxter. Plate XLIII, figs. 7-8. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXVIII, p. 26. June, 1S02. 



Receptacle pale dirty brownish, becoming gradually somewhat broader distally, the foot blackish 

 brown, not clearly distinguished, the subbasal cell longer than the basal. Stalk-cell of the perithecium 



