of the Southern portions of South America. 51 



I sent my descriptions to a recent number of the ^ Annals.' Find- 

 ing however in a specimen in my collection (one which had been 

 brought home by Mr. Bridges) certain characters w4iich I regarded 

 as important, I requested to be allowed to re-examine Mr. Bridges' 

 collection, and was immediately satisfied that it contained two new 

 species allied to G. Hopei, and many specimens of both sexes of 

 each, and although they have a common superficial resemblance 

 they are easily distinguished. G. Hopei differs from the other two 

 species in having the prsesternum broader and not continued be- 

 hind the line of the coxae of the anterior pair of legs. In G. Whitei 

 and G. Bridgesii the prsesternum is contracted, keeled, pointed 

 behind and produced beyond the coxae. In the form of the thorax 

 the present new species agrees most nearly with Hopei ; that is, 

 in having the sides, from the middle to the posterior angle, nearly 

 straight and parallel, and in having the diameter, in the longi- 

 tudinal direction of the insect, greater. The thorax in Bridgesii 

 gradually widens from the apex to the base, and it is shorter than 

 in Hopei and Whitei. The reflected margin of the thorax in 

 TVhitei is broader than in Hopei ; in Bridgesii it is but indistinctly 

 marked. Lastly, in Bridgesii the dorsal surface of the thorax has 

 numerous strong rugae — irregular, but for the most part longitu- 

 dinal in their direction, and in this respect resembling G. Luczotii, 

 but in this last-named insect the rugae are rather stronger. In 

 G. Hopei and G. Bridgesii the thorax is smooth, glossy in the 

 former insect, but dull in the latter. The elytra are less convex 

 in Whitei {much less so in the male sex) than in Hopei and 

 Bridgesii, and the suture is but indistinctly keeled ; in Hopei it is 

 not keeled, and in Bridgesii it is strongly keeled. As regards the 

 white lines which adorn the elytra there is a considerable differ- 

 ence. In G. Hopei and G. Bridgesii the white lines are almost 

 entirely confined to the hinder half of the elytron ; on the other 

 portions there are white dots, excepting towards the scutellum : 

 the number of white lines is usually five or six. In G. WTiitei 

 the lines are nearer together, and eleven or twelve, on each ely- 

 tron, may be counted ; they cover the elytra, with the exception of 

 a dorsal patch, which is broad at the base of the elytra, and ter- 

 minates in a point about the middle, or rather behind that part. 

 In G. Hopei and G. Bridgesii the white hues are for the most 

 part parallel with the suture, the exterior ones diverging but 

 little : in G. Whitei they may be said to radiate from a point, 

 and that point at, or near the scutellum. The legs in Whitei are 

 decidedly more slender than in G. Hopei, and in this respect re- 

 semble those of G. Bridgesii. The antennae, as compared with 

 those in Bridgesii, differ in having the terminal joints less dilated. 

 I may mention, that of the G. Whitei I have seen about a dozen 

 specimens of both sexes, of Bridgesii more than double that num- 



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