186 Mr. G, R. Waterhouse on two new genera of 



not distinctly emarginated in front. The most important distin- 

 guishing character however is perhaps that furnished by the struc- 

 ture of the tarsi, the penultimate joint of which is distinctly bilobed 

 and furnished beneath with membranous appendages in both sexes. 

 I fancy I can also perceive similar appendages on the under side of 

 the antepenultimate joint. In the male the whole under surface of 

 the anterior tarsi is covered with small hairs and membranous ap- 

 pendages, and at least the penultimate and antepenultimate joints of 

 the other tarsi are provided with the same soft cushions. Most of the 

 above characters will serve to distinguish Abropus from Antarctia, but 

 in a less marked degree ; some of the species of the last-mentioned 

 genus approaching very nearly to Abropus in their general form, as 

 well as in the structure of the parts of the mouth. The labrum in 

 Antarctia is shorter and broader and more distinctly emarginated in 

 front ; the mandibles are rather more curved and acutely pointed, 

 and one of them has a distinct tooth on the inner side ; the labrum 

 differs only in being shorter and broader ; scarcely any difference is 

 perceptible in the palpi or in the maxilla?. Whilst, on the one hand, 

 I find species of Antarctia with the narrow thorax and general form 

 approaching Abropus, on the other, I find species which I can scarcely 

 say differ from Metius ; — the Antarctia carnifex of Dejean, for ex- 

 ample, might with perfect propriety be placed in the genus Metius. 

 Plate III. fig. 1 a, head magnified ; 1 b, menlum ; 1 c, fore tarsus of male. 



Mr. Darw T in found the Abropus splendidus flying in numbers about 

 the sea- coast in the evening in the month of December. " These 

 insects live amongst the soft yellow balls which are excrescences, or 

 rather fungi, growing on the Fagus antarctica, and which are eaten 

 by the Fuegians." 



Some specimens were found by Mr. Darwin under bark at Port 

 Famine in the month of February. 



MIGADOPS*, nov. gen. 



Caput latum, subdepressum : labrum transversum, antice emargina- 

 tum : mandibulce intus bidentatse : mentum emarginatum, dente 

 medio, lato, ad apicem bifido, instructum : palpi articulo ultimo 

 mediocriter elongato, in medium paulo incrassiore, ad apicem in- 

 distincte truncato : antenna mediocres. 



Thorax transversus, elytris angustior. 



Elytra ovata. 



Pedes mediocres : tibia anteriores intus emarginatae : tarsi quatuor 

 anteriores in maribus dilatati et articulis transversis, subtus spon- 

 giosis. 



Sect. A, with the four anterior tarsi distinctly dilated in the male sex. 



Sp. Migadops virescens, Plate III. fig. 2. Mig. niger, supra vires- 

 cens ; antennis pedibusque rufo-piceis ; capite lato, subdepresso ; 

 thorace transverso, subquadrato, ad latera in medio paulo dilatato, 



* From piyoig, mixed, and u-^*, the countenance, aspect, &c. the species 

 ^f the genus having the general aspect of one division of the Carabi, but an 

 ffinity to another. 



