DIPTKRA. ISi 



Of those in wliich the antennae are much shorter, the 

 Xestomyza, Wied.. 

 Aj)proximatcs to Toxophora in the lengtq of the first) joint of those 

 organs, which is considerably greater than that of the others; it is 

 almost fusiform, as well as the third or last*. 



Apatomyza, Wied.., 



Is another subgcmis in which the first joint of the antennae is also 

 very long ; but here that joint is cylindrical f. 



In the folloAving subgenera of the same division, or of those whose 

 proboscis is long and setaceous, or filiform, the last is the longest. 



Sometimes the two first joints of the antennae are short and almost 

 of equal lengtl). 



Lasius, Wied., 

 Where the head, in one of the sexes, is almost entirely occupied by 

 the eyes, and the last joint of the antennae is very long, almost linear, 

 compressed, and without any apparent terminal seta. Tlic abdomen 

 is voluminous. The lahrum is large, gibbous at base, and truncated 

 at the end. 



In one specimen, for Avhich I am indebted to the kindness of M. 

 de Lacordaire, the proboscis extends along the under part of tlie body 

 and projects beyond its posterior extremity. This character, with 

 some others, Avould seem to indicate that this subgenus naturally be- 

 longs to the tribe of the Vesicularia, and comes near Panops J. 



UsiA, Lat. — VoLUCELLA, Fab., 

 AVhere the last joint of the antennae is ovoido-conical,' obtuse or 

 truncated at the end, aud terminated by a stilet. The palpi are not 

 apparent. 



The species are peculiar to the southern countries of Europe 

 and to Africa §. 



Phthiria, Meig. 

 Similar to Usia in the antennae, but the palpi are distinct ||. 

 Sometimes the second joint is evidently shorter than the first ; the 

 last is long, generally almost cylindrical, and terminated in a point, 

 as in 



BoMBYLius, proper, 

 'W'^here the palpi are very apparent. 



These Insects are densely covered with a woolly down, which co- 

 lours it. The most common species in the environs of Paris is the 



B. major, L. ; B. bickon, De Gecr, Insect., VI, xv, 10, 1]. 

 From four to five lines in length, and entirely covered with yel- 

 lowish-grey hairs ; proboscis long and black ; external half of 

 the wings blackish, the remainder diaphanous ; legs fulvous. 



* Wied., Dipt., Exot., 15:5, I, H. 



t Id., Ibid., III. I have never seen a species of this genus. 



:i; V/ied., Anal. Entom., I, 3. 



§ Lat., Gener. Crust, et Insect., IV, 314. See also Fab. abd Meig. 



II The same works. 



