A Monogra-ph of Egyptian Diptera. 75 



generally the hairs are t'ouiid on a liinited space of the upper 

 part, except in E. toiicur, wherc the hairs are nuich more numerous 

 and arranged in danser lines. xVntennîe moderate in shape and 

 length, the third joint always bearing near its base a bare arista. 

 Thorax quadrate, in sorae species bearing f airly conspicuous light 

 markings, and in others quite f aint ones ; it is more or less densely 

 pilose ail over, without any trace of bristly hairs. Scutellum eqiial- 

 ly pilose with the thorax and usiially yellowish and translucent 

 (except in E. œiieus). 



Abdomen moderate in shape, ranging in colour f rom a uniform 

 seneous-black to being largely covered with orange, white and black 

 markings; it varies in shape and in pilosity with différent spe- 

 cies. Legs almost simple in construction but with the hind tibise 

 nearly always curved and with variable ciliation. Wings special- 

 ised by the closed Ri cell and by the deep loop in Radius 4 + 5 

 over the middle of cell R5, thèse characters distinguishing them 

 from the wings of any other Egyptian Diptera. 



SYJ^O^sYMY : — In 1857 Rondani separated off the European 

 species with a plnmose arista into a limited genus Erlstaiis, after 

 which the species with a bare or almost bare arista hâve been 

 broken up into varions subgenera. Rondani, who made the first 

 attempt, suggested Eristalomyia for the species which hâve the 

 eyes touching in the maie and thus created a genus Eristalinns for 

 a single species {E. sejndehralis) in which the eyes are well separ- 

 ated in the maie. This induced Mik in 1897 to further subdivide 

 the genus. He suggested that the species with a haie arista 

 should be sei^arated into 4 gênera of which the first should be 

 Eristnlomyia with its type E. tcnn.r, which lias the eyes unicolo- 

 rous. As Verrall states, it was unfortunate for bis generic dis- 

 tinction that E. tena.r has two bands of darker i^ubescence running 

 down its eyes, which form its most distinctive spécifie character; 

 Verrall further admits that thèse bands are caused by pubescence 

 and are longitudinal, so that they do not traverse the generic or 

 subgeneric rank. After Eristalis, Mik separated off the species 

 with what he called "oculi picti" which one would translate as 

 "eyes with markings," and on this basis he formed a genus Erista- 

 lodes, in which the eyes hâve five obscure transverse stripes, and a 

 genus Lathytoplithaliniis which is distinguished from Rondani's 

 Eristalinus simply because the eyes of the maie approximate in 

 LatMjroj)hthaltnus and do not api^roximate in Eristalwvs. 



Moreover the species of this genus ail show a close relation- 

 ship to each other in their stout solid shape (even in the very 

 numerous European species), so that no confusion should arise as 

 to their position in this family and I cannot help agreeing with 



