250 CULICTD.F-. 



Genus IV. CORETHRA. 



CORETHUA, Meig. Illig. Mag. (1803); Latr. j Panz. j Mcig. ; Steph. ; 

 Mcq. ; Zett. ; Gim. ; StEeg. ; Westw. Tipula p., L. ; F. E. S. ; 1). G. ; 

 Gmel. ; Meig. Kl. Chironomus p., F. S. A. Tanypus p., Lam. 



Corpus mediocre aut parvum, elongatum, pubescens. Caput parvura, 

 sessile. Oculi transversim lunati, subremoti. Os parvum, subelon- 

 gatum. Proboscis antennis multo brevior. Palpi 4-articulati, cylin- 

 drici, pubescentes, incurvi, articulus primus brevis. Antermte 14- 

 articulatae, porrectae, filiformes, thoracis longitudine. Thorax longi- 

 ovatus. Scutellum mediocre. Alae angustse, pubescentes, incurn- 

 bentes, squamis ciliatae, abdomine paullo breviores. Abdomen seg- 

 mentis 8, gracile, elongatum, pilosum. Pedes graciles, pubescentes, 

 inermes, sat longi. Mas. Antennae verticillato-plumosa3. Abdo- 

 men apice valvulis duabus foliaceis subincurvis sat longis instructum. 

 Fcem. Antennae verticillato-pilosae. Abdomen apice hamulis duobus 

 brevibus instructum. 



Eody of moderate size, elongate, pubescent. Eyes transversely lu- 

 nate, separate in both sexes. Mouth small, slightly elongate. Pro- 

 boscis much shorter than the antennae, with two apical clavate appen- 

 dages. Palpi four-jointed, cylindrical, pubescent, shorter than the an- 

 tennae ; first joint shorter than the others. Antenna fourteen-jointed, 

 porrect, filiform, as long as the thorax. Thorax elongate-oval. .Scutel- 

 lum of moderate size. Wings narrow, pubescent, a little shorter than 

 the abdomen, incumbent during repose ; veins fringed with scales ; me- 

 diastinal vein ending at about half the length of the wing ; subcostal 

 ending at full five-sixths of the length ; radial springing from the sub- 

 costal at before half the length of the wing ; its two forks ending at 

 the tip of the wing ; cubital proceeding from the prsebrachial transverse 

 veinlet ; subapical forked towards its tip ; praebrachial, subanal, and anal 

 complete; posterior margin excavated at the base. Abdomen slender, elon- 

 gate, hairy, with eight segments. Legs slender, moderately long, pilose, 

 unarmed ; fore pair not remote from the others ; coxae of moderate size ; 

 ungues very small ; onychia almost obsolete. Male. Antennas verticil- 

 late-plumose, the whorls from the base to the tips successively decreas- 

 ing in length. Abdomen with two apical, slightly curved, foliaceous 

 appendages, nearly as long as one of the segments. Jem. Antennae 

 verticillate-pilose ; hairs short and few. Abdomen with two little 

 apical curved hooks, which are not longer than a quarter of one of the 

 segments. 



" The larva of Corethra plumicornu is so beautifully transparent 

 as to resemble a piece of crystal, and scarcely to be distinguished 

 from the water in which it lives. It is vermiform, very long, 

 with rather thicker thoracic segments. The head is small, co- 

 nical, turned upwards, furnished with two deflexed hooks, which 



