254 Mr. J. O, Westwood on JEvania and 



Sp, 7. Monomnchus falcator, King. MSS. (spec, indescr.) 

 Habitat St. Joan del Rey. Sello. 



Obs. C, Darwin, Esq., brought home a species of this genus, 

 which has for some time past been in the hands of W. E. Shuckard, 

 Esq., for description. 



The three following genera are at once distinguished from the 

 preceding by having the ovipositor long and exserted. 



FcENus, Fabricius. 



This genus is remarkable on account of several peculiarities which 

 it exhibits. The strongly dentated mandibles, the minute tongue- 

 like labrum, the antennae composed of thirteen joints in the male 

 and of fourteen in the female, the elongated prothorax forming 

 a long neck, the singular posteriorly dilated parapsides of the 

 mesothoracic scutum (giving the appearance in some species of a 

 separate subsegment), the insertion of the abdomen close to the 

 mesoscutellum, the clavate hind legs, and the curious arrangement 

 of the veins of the wings (PI. XV. fig. 2), are all exceedingly 

 characteristic, and render this one of the most isolated genera. 

 I have illustrated the majority of these characters with figures in 

 the *' Introduction to the Modern Classification of Insects," 

 vol. ii. p. 1S4. 



Latreille appears to have dissected a female, since he describes 

 only the mandibles of that sex; and Mr. Curtis, who dissected 

 F. assectator, figures these organs as of a different form in the 

 two sexes. In all the specimens of F. jnculntor, austraUs, and 

 7inguiculatus, which I have dissected, including males and females, 

 they were alike in form, all having a very strong and acute basal 

 tooth within, which appears wanting in the male of assectator. 



The labium also in F. jacidator and unguiculatus was -much 

 longer than in Mr. Curtis's figure. 



The inferior wings are destitute of cells, the veins being almost 

 obsolete. 



The following is a monograph of all the species of the genus 



