582 THEREVID^ 



" burrows," this fly being T. annulata ; this habit agrees with the record 

 made by Dahlbom concerning Crabro patellatus and Dialineura anilis. 

 My dates range from May 6 to August 26. It is recorded from all 

 Northern, Western, and Middle Europe; I possess several specimens 

 from Cintra. 



2. DIALINEURA. 



Dialineura Eondani, Dipt. Ital. Prodr., i., 155 (1856). 



Face bare ; frons hairy (fig. 326). Antennae with the basal 

 joint conspicuously incrassated. Wings with the fourth 

 posterior cell wide open. 



Via. B'i&.—Dialinmr a anilis i. x 25. 



This genus is distinguished from Tlicrcva by its bare face and con- 

 spicuously open fourth posterior cell (though Thcrcva varies in this latter 

 character), and from Fsilocephala by its hairy frons and its entirely 

 different " facies," and from both by its conspicuously dilated basal 

 antonnal joint ; the frons of the female is also without the shining black 

 bare calli which commonly occur in Thercva. The species of Psiloccphala 

 are elongate oblong flies, while in Dialineura. the abdomen is conical and 

 densely pubescent like Thercva. 



Sywonymy, — Rondani founded the genus Dialineura as follows : " A. Vence 

 " lonr/itudinales octava et nona sejunctim margini alarum productiB. — Antenitcp 

 " articulo prime distincte incrassato." " Genus 1 Dialineura Mihi.'' 



The character of the open fourth posterior cell has been found extremely un- 

 trustworthy, but Rondani's second character holds good, and that in conjunction 

 with the entirely overlooked character of the bare face has induced me to retain the 

 genus for D. anilis only. Every writer seems to have described the face of D. anilis 

 as pubescent, and I can only imagine that they have been misled by the hairy palpi. 



1. D. anilis Linne. Abdomen of the male entirely clothed with 

 silvery pubescence, but the thorax light brown. Female without any 

 shining black frontal callus, and with the femora all orange. 



A very distinct species. Possibly a mimic of Scatophaga. 



(^ . Frons and face forming a bell-shaped space which is broader than high ; 

 frons moderately produced to the base of the antenuce, but the face sloping 

 back straight from there to the front lower corner of the eye ; frons covered 

 with yellowish brown dust, separated from the whitish yellow face by a more 



