DIPTEEA. 291 



7. Phthiria sororia, sp. n. 



$ . Head yellow ; ocellar tubercle and the beginning of a stripe below it brown. Antennae black, the first 

 joint yellow, and of nearly the same length as the second. Palpi shorter than the head, black ; proboscis 

 about three times the length of the head. Thorax yellow ; mesonotum with three broad, nearly confluent, 

 ochraceous or brownish stripes ; pleurae with two or three small spots of the same colour. Abdomen 

 yellowish-red, sometimes variegated with brownish. Legs yellow ; tibiae darker, the tarsi blackish 

 toward the tip. Wings tinged with yellowish on the basal portion, brownish distally ; no adventitious 

 vein in the discal cell. The pile everywhere yellow. Length 6 millim. 



Eab. Mexico, Chilpancingo and Arrmla in Guerrero (E. E. Smith). 



Fifteen specimens. The fact that these are females, while all those of P. dolorosa 

 are males, together with the infuscation of the wings in both, may indicate that they 

 belong to one species. There were none collected together, however, and the 

 extraordinary difference in coloration would seem to make it highly improbable that 

 such could be the case. 



8. Phthiria thlipsomyzoides. 



? Pcecilognathus thlipsomyzoides, Jaenn. Abh. Senckenb. Ges. vi. p. 351 \ 

 Hob. Mexico 1 , Amula in Guerrero (H. E. Smith). 



A single female. This specimen differs not a little from Jaennicke's description of 

 the male, and as there are several concurrent species here, it is possible that our insect 

 may belong to some other male. For that reason I give a description of it : — 



$ . Front ochraceous, on the sides light yellow, opaque, the ocellar tubercle and a spot in the centre black ; 

 strongly depressed in the middle longitudinally, the lower half shining and with black hair. Sides of 

 the face very broad, shining yellow, with two large, nearly confluent black spots ; oral opening nearly 

 vertical in profile. First two joints of the antennae yellow, the first about as long as the second, and 

 both with black hair above ; third joint rather narrow, tapering at the distal end only, black, yellow at 

 the base. Proboscis and palpi black, the former nearly three times the length of, and the latter a little 

 shorter than, the head. Mesonotum with three rather broad, narrowly separated stripes ; posterior part 

 reddish-yellow ; sides more purely yellow. Scutellum light reddish-yellow, the margins broadly light 

 yeUow. Pleurae for the most part light yellow. Abdomen obscurely brownish or reddish-yellow, with 

 the segments blackish anteriorly. Legs reddish-yellow, the tarsi in large part black. Wings hyaline, 

 the tip broadly margined with brown ; costal cell yellowish, the subcostal brownish ; small brown spots 

 on the basal cross-veins, the anterior cross-vein, the furcation of the third vein, the posterior basal cross- 

 vein, and the vein at the base of the third posterior cell. Length 10 millim. 



The neuration of both wings is anomalous, in that the discal cell is confluent with 

 the second posterior cell ; there is also a stump of a vein on the second longitudinal 

 vein opposite the anterior cross-vein. P. thlipsomyzoides was not identified by Osten 

 Sacken in the earlier part of this work (antea, p. 156). 



9. Phthiria alterans, sp. n. 



$ . Very like P. thlipsomyzoides, but with the sides of the face nuch narrower. Front opaque brownish and 

 yellow on the upper part ; below the transverse groove shining light yellow, with a large brown spot in 

 the middle ; face shining yellow, with two dark brown spots ; oral opening nearly vertical. First two 



2^2 



