336 INSECT A. 



Two species, one of wliicli — Ct/therea fasciata, Fab. — is found 

 in Italy and in ci-dcvant Provence, differ but little as to the re- 

 ticulation of their wings from the Anthraces. They form the 

 genus Fallenia of MM. Mcigcn and Wiedemann. According 

 to them, the proboscis is susceptible of being curved beneath 

 and along the pectus *. 

 The genus Colax of Wiedemann — Anal. Entom., xviii, fig. 8 — in 

 general appearance, antenna?, and Avings, appears to us to ajsproxi- 

 mate in the last mentioned Anthraces, but according to that gentle- 

 man the oral cavity is closed as in CEstrus, and the ocelli are wanting. 



Our second general division of the Tanystoma is characterized by 

 a membranous proboscis, usually with a short stem, projecting but 

 slightly and terminated by two very distinct and raised or ascending 

 lips. 



The form of the head in the larvae of the last Diptcra of this divi- 

 sion is variable. 



In some — Leptides — the wings are distinct, and exhibit several 

 complete cells. The antennae are not terminated en palette. The 

 palpi are filiform or conical. 



Sometimes these palpi arc withdrawn into the oral cavity. The 

 antennae have a fusifoiTn termination or one resembling an elongated 

 cone, with a little articulated stilet at the end \. 



Thereva Lat., Meig. — Bieio, Fab., 

 To which belongs the following species. 



T. plebcia ; Bibio pleheia. Fab. Black, with cinereous hairs ; 

 abdominal annuli margined Avith white. On plants. 



The larva of a species of this genus — Nemotelus hirtus, De 

 Geer — lives in the ground and resembles a little serpent. Its 

 body is Avhite and pointed at both ends. It changes the whole 

 of its skin when about to become a pupa %. 

 Sometimes the palpi are exterior. Tlie last joint of the antennsc is 

 either almost globular or reniform, or nearly ovoid or conical and ter- 

 minated by a long seta. 



The tarsi are furnished with three pellets. They form the genus 



Leptis, 



Which is divided into several subgenera. 



Athekix, Mei(j., Fab., 

 Where the first joint of the antennae, larger than the second, is thick, 



* See tbe autbors already quoted, and tli? Encyc. Mc-thod., article Newcsfrine. 



t This subdivision corresponds to the f;in;ily of the Xyhtuma of MM. Meitren 

 and Macquart. 



X Lat.; Ibid., Fab., Meig. and INIacquart. In the collection of Faujas, I saw a 

 piece of schist that exhibited the impression of a species of this genus. 



