OSTEN SAC KEN ON WESTEEN DIPTERA. 203 



The stature and general appearance are those of a LimnophUa. 



Antenn(e, when bent backward, nearly reach the root of the wings ; the 

 joints of the scapus have the usual structure ; the flagellum is not per- 

 ceptibly stouter at the base than at the end ; the joints have that sub- 

 cylindrical shape, attenuated at the point of insertion and verticil-bear- 

 ing about the middle, which is quite common among the LimnopMlina; 

 they gradually decrease in length toward the end and become more 

 oval; verticils short; front moderately broad. Yertex but moderately 

 convex. 



The legs are long and slender, with an almost imperceptible pubes- 

 cence ; the spurs at the end of the tibiae are very distinctly seen under a 

 magnifying power of 100 to 150. The ungues and empodia are exceed- 

 ingly small. 



The tpm^s are of a moderate length and breadth; the venation has 

 been partly described above; the stigma is well defined, oval, placed 

 at th6 end of the first vein. The preefurca has very little curvature at 

 the base, and is not much longer than the petiole of the fork of the 

 second vein ; the second submarginal and first posterior cells are of 

 equal length, their bases being nearly on the same line; the sides of 

 the first posterior are almost parallel ; the structure of the discal cell 

 shows that it is formed by the forking of the posterior branch of the 

 fourth vein, connected by a cross-vein with the anterior branch; the 

 great cross-vein is at the bifurcation of that posterior branch, and thus 

 a little beyond the middle of the discal cell. 



The genitals of the male are very large and club-shaped, resembling 

 those of a Tipula more than those of a LimnophUa. The following is 

 the description of the forceps of P. pallida, as I do not possess the male 

 of the other species : — 



The last upper abdominal halfsegment is uncommonly large and 

 convex; two large basal pieces of the usual shape, bearing a small, 

 curved, pointed rostriform appendage at the end, and some branched 

 and hairy inner appendages; on the under side of the forceps, and en- 

 tirely detached from it, is a very characteristic yellowish- white elongated 

 foliaceous appendage, folded lengthwise and bifid at the tip. 



The female has the last abdominal segment likewise distinctly swollen, 

 especially when seen from the side. 



Stigma pale brownish ; antennae uniformly black claviger. 



Stigma dark brown ; two basal joints of the antennae pale 



brownish ; the rest black encausta. 



Phyllolaeis claviger n. sp. — Head gray, with a shade of brownish 

 on the front; antennae and palpi black. Thorax gray, with three ill- 

 defined brownish stripes, the intermediate subgeminate ; halteres yel- 

 lowish-white ; knob sometimes faintly infuscated. Abdomen grayish- 

 brown ; male forceps brown : foliaceous appendages yellowish-white. 

 Legs brown; cox;e and base of femora brownish-yellow. Wings gray- 

 2 II B 



