452 MODERN CLASSIFICATION OF INSECTS. 



Gryllus viridissimus ; ^^. 55.3 — 13. details of the same insect) is 

 short and vertical, but occasionally acuminated in front (as in the 

 genus Conocephalus). The upper lip is rounded and entire, the 

 palpi of moderate length, with the basal joints short; the lower lip is 

 composed of four divisions, of which the lateral ones are by far the 

 largest. {Fig. 55. 3. represents one of the mandibles ; 55. 4. max- 

 illa ; 55.5. labrum; and 55. 6. internal lingua of G. viridissimus.) 



The anterior tibiae are somewhat dilated at the base, where there is 

 an oval aperture, closed on each side by a talc-like plate * (^fig. 55. 

 17. tibia of Scaphura) ; and which exists in both sexes, so that 

 it is not connected with the powers of stridulation. The third 

 joint of the tarsi is ordinarily dilated, so as to appear bilobed, and 

 the basal joint of the posterior tarsi is often lobed on each side. On 

 inspecting the tarsus on the underside, the basal joint exhibits a 

 transverse impression, as though indicating the presence of two joints 

 soldered together (Jfff. 55. 9. hind tarsus laterally ; 55. 10. ditto, seen 

 beneath.) The three thoracic sternums, or one of them at least, 

 are provided with corneous points, varying in the different species 

 (Jig. 55. 7.), upon which character Serville has established some of 

 his genera. Brulle, however, denies its importance ; and I cannot but 

 agree with him, at least to a certain extent. 



The wing-covers of the males are furnished at the base, near the 

 suture, with a round talc-like plate f, surrounded by strong ridge-like 

 veins, one on the underside, towards the internal angle of the left-hand 

 wing-cover, being stronger than the rest, and serving as a bar to 

 produce the sound upon rubbing the two wing-covers sharply over 

 each other. The two plates are not symmetrical (Jig. 55. 14. sutural 

 portion of the base of the left-hand; 55. 15. ditto, of the right-hand 

 wing-cover of G. griseus), and the insect would remain mute, were 

 it not to fold its wings in the ordinary manner, the left cover being 

 generally laid over that on the right-hand side. These organs, and 



* In some species the talc-like plate is less distinctly visible, being partially co- 

 vered over by an operculum composed of the integument of the limb itself (^^. 55. 8. 

 base of tibia of G. viridissimus. ) 



t These eye-like spots were first noticed by Lichtenstein, as indicating the male 

 sex, in a memoir published in the fourth voluine of the Linncean Transactions. 

 Tiie Rev. L. Guilding has also described them in the fifteenth volume of the same 

 Transactions, and his figures have been published by Donovan in the Naturalists' 

 Repository, pi. 122, 123., representing Gryllus camellifolia Fah., a species the stridu- 

 lation of which is so loud as to be heard at the distance of a mile. 



