v^ 



42. 

 PACHYGASTER LEACHII. 



Order Diptera. Fam. Stratiomydae Lat., Leach. 



Type of the Genus Vappo ater Fab. 

 Pachygaster 3Ieiff. Vappo Lat., Fab. Nemotelus Fz. 



AntemicB approximating, porrected, hairy, 3-jointed, first joint 

 small, second large, transverse, third large, somewhat hemispheric, 

 compressed, having a reticulated appearance under a lens, and 3 

 indistinct transverse rings (Meigen says 4) with a hairy seta at- 

 tached to the outer side near the extremity. (3.) 

 Labrum horny, robust, cylindric, grooved beneath, dilated at the 

 base, obtuse and notched at the apex. (1. b.) 

 Tongue horny, acute, attenuated from the base, shorter than the 

 labrum. (c.) 

 Mandibles none. 



MaxillcB long, slender, acute, concealed in the lip. (e.) 

 Palpi 2, oblong, cylindric, very minute, slightly pilose, attached 

 to the base of the maxillae, (f.) 

 Mentum large, cylindric, inclining upward, (h.) 

 Lip fleshy, large, oval, bipartite, pilose, (g.) 

 Proboscis shorter than the head, concealed when at rest. Eyes approxi- 

 rdating above in the males. Ocelli 3, placed anteriorly in the males, 

 posteriorly in the females. Thorax obovate, with a transverse suture. 

 Scutellum tcithout spines. Abdomen large, nearly globular, being 

 convex above, composed of 5 obscure segments. Legs simple. Tarsi 

 ^-jointed, with 2 claics and pulvilli (8. afore leg.) Wings incumbent, 

 when at rest placed parallel upon the abdomen, long, lanceolate, nerves 

 very faint. Halteres large, ovate. 



Leachii Stephens' MSS. 



Black, shining, punctured. Antennae orange, eyes purplish or 

 slightly red, legs pale straw colour, the posterior thighs with a 

 black spot near the apex. Halteres fuscous. Wings entirely 

 transparent, iridescent, nerves very pale brown. 



In the Cabinets of the British Museum and the Author. 



Pachygaster ater is the only insect of this Genus hitherto de- 

 scribed ; it is figured by Panzer, is somewhat larger than our 

 insect, and is at once distinguished by its wings, which are brown 

 nearlv half way from the base. P. Leachii appears to be very 

 rare, the only specimens discovered, being a male in the Cabinet 



