New Species of Hymenoptera. 329 



SiBYLLINAj n. g. 



Genus novum Acideatoruvi, quoad affinitates animum 

 excrucians^ sed ad familiam Vespidarum ut milii 

 videtur magis approximans. Corpus elongatum, 

 Belonogastri {Vtspidarum) vel Pelopcei [Sphegida- 

 rum) habitu, cJ etiam Formicarum nonnullarum 

 antennis elongatis^ non dissimile. 



Caput mediocre. Oculi reniformes. Ocelli magni. 

 Mandibulge parv^e, 3-dentatge. Antenna ? graciles, fili- 

 formes, alis longiores, 12-articulat£e, non geniculatse^ arti- 

 culo Imo parvo. Palpi valde elongati, 6-4-articulati. 

 Labium^ ut videtur, 3-lobatum. Thorax elongato-ovatus, 

 collare brevi, lateraliter ad tegulas extenso, in medio sub- 

 tus profunde impresso. Petiolus abdominis thoracelongior. 

 Abdomen elongato-ovatum. Pedes longi, graciles, baud 

 spinoso-denticulati ; tarsia omnibus elongatis, mem- 

 branaceo-dilatatis ; unguibus dente medio subtus arma- 

 tis. Alte mediocres ; anticae baud longitudinaliter plicatge ; 

 cellula una marginali, 3 submarginalibus, Ima et 2da 

 £equalibus, 2da accepit venam lam recurrentem valde 

 obliquam in medio marginis postici ; 2da recurrente, valde 

 indistincta, cellulam 3am discoidalem claudente, trans- 

 versa, et apicem cellul^e 2d£e attingente ; alae posticse ad 

 apicem vena3 pobrachialis incisae. 



Sibyllina cenigmaiica, n. sp. 



Tota luteo-fulva ; lasvis, vix nitida ; alis lutescente vix 



tinctis. Ophioni luteo coloribus similis. 

 Long. corp. unc. \', expans. alar, antic, unc. f. 

 Habitat in Insula St. Dominici, Hayti. Dom. Tweedy. 

 In Mus. Hopeiano, Oxoniee; Britann.; et Dom. Smith. 



Genus Aulacus, Jurine. 



The following descriptions of new species are supple- 

 mental to those published by me in the Third Volume of 

 the First Series of these Transactions (p. 260), and the 

 First Volume of the Second Series (p. 222) . 



1. Aulacus nohilis, n. sp. 



Niger, nitidus ; mesonoto valde gibboso, retuso, rugoso, 

 et antice tuberculis duobus conicis porrectis armato. 



