248 



spicuo. Arista quasi exarticulata, non nisi dorso pectinata. Alulae 

 auricula interfere quasi nulla*. Vena mediastina cum subcostali con- 

 nata, ala3 trientem longitudinem vix pertingens. Areolce pobrachialis 

 et analis perparvae, modo non semper incomplete^. Oviductus foeminse 

 plane reconditus^:. Tibia3 anticse et posticse setis lateralibus ex- 

 pertes. 



Face convex, without membranaceous furrows. Peristoma round. 

 Mentum short, thick. Antennae short ; first joint indistinct ; fourth and 

 fifth obsolete ; sixth never pectinated beneath. Subcostal and medias- 

 tinal veins united, hardly extending to one-third of the length of the 

 wing. Pobrachial and anal areolets very minute, if not always incom- 

 plete. AlulaB with the lower valve obsolete. Pore and hind tibia3 

 without lateral bristles. Fern. Oviduct concealed. 



" None of this, except the singularly-formed Musca mantis of 

 De Geer, had been described before the appearance of Fallen's 

 essay in the ' Stockholm Transactions' for the year 1813, in which 

 the tribe first assumed a distinct character and definite limits. 

 The author has here described nineteen genuine species, and cha- 

 racterized most of the genera ultimately admitted. The Dolicho- 

 pidae were included in this tribe in the first sketch of his arrange- 

 ment of Diptera, published three years before. Latreille adds to 

 the tribe the exotic genus Eopalomera, and excludes from it the 

 type of Fallen's genus Hydromyza, Musca livens of Fabricius, re- 

 ferred to the Cordylurte in accordance with Meigen's arrangement. 

 E. Desvoidy has also placed with his Hvdrettidea a group of 

 Cordylura less aberrant (than C. livens) from the ordinary cha- 

 racter; the type of his genus Nupharia being the C.fraterna of 

 Meigen. Macquart, remanding Hydromyza and Nupharia to their 

 proper place among the Cordylura, has further limited the Hydro- 

 myzida, by rejecting all the species which have not the arista 

 pectinate. These he has placed in his family Piopkilida, in con- 

 junction with many genera of diversified character and remote 

 affinity. 



"The tribe, as described by Fallen in his 'Diptera Suecise/ 

 where he removes Hydromyza to the Scatowyzidtz, and rejects the 

 addition of Ropalomera, is one of the most remote from the Ca- 

 lyptrate section, and can scarcely be confounded with any other 



* A little more apparent in Ochthera. 



f For an exception see Ephydra nasica. The imperfection of the same areolets 

 is a character of the Oscinida also; but in that tribe they become incomplete after 

 attaining their full development in the Loxocerida. This appears as well from the 

 indication of their limit in the thickening of the veins and the corresponding divari- 

 cation of the radial and cubital veins, as from the analogy of the last-named tribe. 



\ There is a slight exception in the subgenera Glenanthe and Teichomyza. 



