94 Psyche [April 



characters of the two forms. X. peruanus has short but pro- 

 nounced abdominal macroeluetse, abdomen subcylindrical in male 

 and nearly same but shorter in female, the black of wings graduates 

 into the subhyaline, the femora are blackish, the face golden 

 especially in male, the abdominal triangles are shining blackish 

 to black, the tegulae are pale yellowish to whitish, the scutellum 

 wholly black and thoracic vittae more clearly defined. Acaulona 

 shows the distinctive facies of the Trichopodice in the male sex, 

 and rather that of the Polistomyiice in the female sex, only lacking 

 the cilia of hind tibiae. 



Pu pari urn — Rather short -stout in form, swollen. The anal 

 stigmatal plates are broad, contiguous, closely approximated, 

 each nearly as broad as long, not raised; the three slits are ridge- 

 like and obliquely disposed, being at about 45° angle to both axes 

 of the plates, rather short and sharply linear, a very little raised, 

 their bases swelling. 



(4) From the same lot of 594 adults of D. rujicollis there was 

 also found issued October c 29, 1912, with the above two specimens 

 of A. peruviana, a third puparium still containing the fly and sup- 

 posed by Mr. Rust to belong to the same species. It proves to 

 be an entirely distinct genus from both Acaulona and Xanthome- 

 lanodcs. The fly has not issued, and the contents are probably 

 dried. The anal stigmata are well produced and prominent, 

 approximated, and the three slits or divisions of each are swollen 

 tuberculate instead of linear ridge-like. 



Puparium — Length about 6 mm., being about the length of the 

 Acaulona puparium but not so swollen. Anal stigmatal plates 

 produced into a rather high process, height about equal to long 

 axis of plate or dorsoventral diameter, each plate rather narrowed, 

 the two approximated but not actually contiguous; the three slits 

 appear tuberculate by reason of their greatly swollen bases, each 

 plate presenting the appearance of three rounded divisions, the 

 axis of slits at about 45° angle to both axes of plates, the slits them- 

 selves apparently irregularly compressed-sinuate. 



