EXTRA-AMERICAN LABOULBENIALES. 741 



divergent, the antheridia turned outward and a little sidewise. Stalk- 

 cell four sided, but subtrianiiular, the three longer sides subequal, the 

 secondary stalk-cell equal, or larger, with a yellow somewhat j^ronii- 

 nent thickening at its upper outer angle which may resemble a sepa- 

 rated cell; the outer basal cell about as large, usually distinctly 

 prominent externally below the venter; which is variably, sometimes 

 considerably and evenly, inflated; or narrower and more or less promi- 

 nently concave below the variably prominent endings of the wall-cells, 

 which hnve a very slight spiral twist; the neck curved outward, stout, 

 typically with broadly spreading base, which may be narrower and 

 followed above by a slight general shallow constriction, or may enlarge 

 gradually to its junction with the tip; which is usually more or less 

 distinctly constricted, bent outward; the apex rather stout, short, 

 with somewhat irregularly compressed lips. Spores 35 X 4 ^u. Peri- 

 thecium 120-140 X 30-35 m- Appendage 42-45 X S-10 /x- Recep- 

 tacle 45-55 X 20-26 fx. Total length 190-225 m- 



On the superior surface of the abdomen of a genus of flies belonging 

 to the Drosophilidae. Kamerun, W. Africa, Nos. 2753 (Type), 

 2668 and 2667 the latter a somewhat smaller species. 



This species, which belongs to the group of forms occurring on 

 Drosophilidae and including S. SigaUocssae, S. Scaptomyzae, S. Droso- 

 philae, is a variable and rather puzzling form. The portions above 

 the receptacle are rather clear, pale, almost lemon yellow. The two 

 lower cells of the appendage appear to represent the normal basal cell, 

 which has divided in two, the lower remaining sterile; while the smaller, 

 upper, bears two antheridia. The habit may be evenly, but not 

 deeply, sigmoid, as in the type; or the axis of the receptacle and venter 

 may be coincident and straight. The perithecium varies greatly, the 

 termination of the wall-cells of the venter abruptly prominent in the 

 type, or the end of the venter narrower and rounded, and subtended 

 by a more or less evident general constriction. The neck may be 

 stout and slightly tapering from a broad base, or more slender, basally 

 constricted, and distally somewhat enlarged, and other variations 

 might be mentioned. The host is a reddish brown drosophilid, with 

 conspicuous longitudinal white lines on the thorax which contrast 

 with a dark edging. I have been unable to obtain a determination 

 of the genus of which more than one species is probably represented 

 in the host material. 



