238 INSECTA. 



The remaining Heterogyna are solitary Insects. Each species is 

 composed of but two kinds of individuals, winged males and apte- 

 rous females ; the latter are^ always armed with a powerful sting. 

 The antennse are filiform or setaceous, and vibratile ; their first and 

 third joints are elongated, and the length of the first is never equal to 

 the third of the total length of the whole organ. 



They form the genus 



MuTiLLA, Lin.* 



In some species, of which the males only have been observed, the 

 antennae are inserted near the mouth, the head is small, and the ab- 

 domen long and almost cylindrical, as in 

 DoRYLUS, Fab. 



Insects peculiar to Africa and India f. 

 Labidus, Jur. 



Hymenoptera of South America, differing from the Doryli in their 

 mandibles, which are shorter and narrower, and in their maxillary 

 palpi, that are at least as long as those of the labium, and composed 

 at least of four joints ; in Dorylus, they are very small and at most 

 biarticulated %. 



In the others, the antennae are inserted near the middle of the face 

 of the head, which is larger than in the preceding Insects ; the abdo- 

 men is sometimes conical, and sometimes ovoidal or elliptical. They 

 form the genus 



MuTiLLA, proper. 



These Insects are found in hot and sandy localities. The female 

 runs with great quickness, and is always seen on the ground. The 

 males frequently alight on flowers, but their mode of life is unknown. 



The species, in the females of which the thorax is almost cubital, 

 and without knots or appearance of divisions above, compose the ge- 

 nera Apterogyna §, PsAMMOTHERMA, and MuTiLLA of Latreille. 

 The abdomen of the Apterogynae has the two first annuli in the form 

 of knots, as in several Formicse. The antennas of the males are long, 

 slender, and setaceous. Their superior wings only present brachial 

 or basilary cells, and a single, small, rhomboidal, cubital cell. In the 

 Psammothermae || and the Mutillae there are three, with two recur- 

 rent nervures. Besides this, the second segment of the abdomen is 

 much larger than the preceding one, and forms no knot. The an- 

 tenuEe of the male Psammothermse are pectinated, and those of the 

 Mutillae simple in both sexes. 



* Tribe of the Mutillaki.e, Lat., Fam. Nat. dn R^gne Animal, 452. 



-]- See Fabricius ; and Lat., Gen. Crust, et Insect., IV, p. 123. 



+ See Jurine and Lat., Ibid. 



§ Lat., Gen. Crust, et Insect., IV, p. 121. See the Diet. Class. d'Hist. Nat.; 

 Dalm., Anal. Entom., 100, where he gives the figure of the Scolia globularis, Fab.j 

 the male of another species of Apterogyna. 



II Mutilla flahellata. Fab. ; the late M. Delalande brought a species of this genus 

 from the Cape of Good Hope. 



