THEREVA. 73 



reva), Lch. Bombyliarii et Xylotomes, Mg. ; Mq. d. e. ; Ags. ; Lw. 

 Bombylica, Brm. Bombyliites, Anthracites, et Therevites, Nwm. 

 Bombylida, Anthracidce, et Therevidce, Ct. ; Wtw. Bombyliarii, 

 Anthracii, et Xylotoma, Mq. d. Bombylince, Anthracmce> et There- 

 vines, Edn. 



Caput rotundatum aut subtransversum. Frons et vertex non impressa. 



Antennae 4-articulatae ; articulus quartus apicalis. Alas divaricatse. 



Pedes tenues. 



Body hairy, rather narrow, of moderate breadth, or broad. Head 

 snbtransverse or rounded. Crown and front not impressed. Ocelli 3. 

 Antennae 3- or 4 -jointed ; fourth joint apical, very short. Wings half- 

 den 1 exed. Halteres uncovered. Abdomen with 7 segments. Legs 

 slender. The genera may be thus divided : 



Genus I. THEREVA. 



THEREVA, LI. g. c. iv. (1809) ; Mg. ; Mq. ; Ztt. ; Lw. Musca p., L. ; 

 Gin. Nemotelus p., Dg. Tabanus p. ? Gf. Bibio p., Fb. ; Mg. 

 kl.; Fin.; Pz. Mydasp., Lm, 



Corpus majoris vel mediae magnitudinis, cylindrico-conicum, sat angus- 

 tum, villosum. Color cinerascens, obscurus, pictura abdominis fas^ 

 ciata. Caput subtransversum. Oculi nudi, virescentes, unicolores. 

 Ocelli 3. Proboscis occulta. Antennae porrectae, 5-articulatae, basi 

 approximatae. Aloe mediocre*, semideflexa. Abdomen obconicum. 

 Mas. Oculi contigui. 

 Fcem. Oculi remoti. 



Body cylindric-conical, of moderate or rather large size, clothed with 

 brown, tawny, or white hairs. Eyes green. Ocelli 3, on the crown. 

 Proboscis withdrawn into the peristoma when at rest. Labrum small, 

 flat, as long as the labium. Lingua small, acute, channelled above. 

 Maxillae small, acute, somewhat shorter than the labrum. Palpi cy- 

 lindrical, one-jointed, hairy on the outside, with a knob at the tip, 

 somewhat longer than the labrum. Labium tumid beneath, chan- 

 nelled above. Antennae 5 -jointed, porrect, as long as the head, 



VOL. I. L 



