300 SYRPHIDTE. 



Genus XXIX. BACGHA. 



Baccha, Fb. s. a. 200. 6 (1805) ; Fin. ; Mg. ; Mq. ; Ztt. ; Ct. ; Rdn. 

 Sijrphus p., Fb. s. i. Musca p., Gml. Bacclia p., St. F. et Srv. 



Corpus gracile. Antennce articulo quarto dorsali. Alee areola sub- 

 apicall Integra, lobo axlllari indistincto. Abdomen petiolatum. Fe- 

 mora postica gracilia. 



Body slender. Head semicircular ; epistoma slightly depressed, 

 with a scapula ; peristoma oblong, narrow, straitened in front. La- 

 brum large, broad, notched at the tip, with a spine in the middle and a 

 smaller one on each side. Lingua stout, lanceolate. Maxillce short, 

 slender, subulate, as loug as the palpi, slightly curved. Palpi clavate, 

 membranous, hairy towards the tips, not half the length of the labrum. 

 Labium short, stout, cylindrical. Antennse 5-jointed, small, approx- 

 imate, porrect, mitant ; first and second joints small ; first cyathiform ; 

 second much shorter and broader, bordered with stout bristles ; third 

 almost round, somewhat quadrate, compressed ; fourth very minute, 

 seated on the base of the third; fifth setiform, stout, rather short, slightly 

 pubescent. Thorax oval. Wings large, with obtuse tips, very finely 

 pubescent, incumbent and parallel in repose ; suJjajiical areolet entire ; 

 axillari/ lobe indistinct. Alula? small. Halteres uncovered. Abdomen 

 pubescent, long, very slender; first segment short, thick in front, 

 narrower behind ; second cylindrical, very slender ; third and fourth 

 somewhat widened. Legs very slender; hind femora not enlarged; 

 hind tarsi hardly dilated. Male. Eyes contiguous. Abdomen obtuse 

 at the tip. Fern. Eyes parted by a narrow linear front. Abdomen 

 acute at the tip. 



The long slender petiolated abdomen is the most apparent dis- 

 tinctive character of this genus. 



1. elosigata, Fb.s.i. ii. 430. 42 (1781); Gm. ; Fin. ; Mg. ; Mq.; 

 Ztt. ; Lw. — sphegina, Mg. — tabida, Mg. ; Mq. ; Ct. — vitripennis, Mg. 

 ^nea, antenuis nigris articulo tertio ferrugineo, scutello pcctoreque 

 chalybeis, alis subcinereis, venis transversis fusco-nebulosis, abdomine 

 cupreo, lateribus fulvo-trimaculatis, pedibus fulvis, tarsis posticis fuscis. 

 Long. 4-4^; alar. 7-8 lin. 



iEneous, head covered with hoary bloom excepting a stripe on the 

 crown and a black shining scapula OTi the epistoma. Antennfe black ; 

 third joint ferruginous. Scutellum chalybeous ; under side of the thorax 

 chalybeous, covered with hoary bloom. JFings slightly grey ; transverse 

 veins clouded with brown ; stigma dark brown. Halteres tawny. Ab- 

 domen cupreous, adorned with three pairs of tawny spots ; first pair 

 suaall, at the base of the thii'd segment ; second pair large, quachatc, 

 partly united, occupying from one-fourth to one-third of the fourth seg- 

 ment from its base ; third pair small, at the base of the fifth segment. 

 Legs tuwnv ; hind tarsi brown. Far. ^. First and second pair of ab- 



