from the Amazons. 475 



and the rest of the surface is reticulated, the areoles being very large 

 and mostly quadrangular. Wings much shorter than the elytra, the 

 median nervures strongly flexuous. 



The stridulating-organs of the male (the only sex known) are of 

 elaborate construction. They are formed, as usual in this family, out 

 of the elements of the small basal portion of the elytra which over- 

 laps when the wing-cases are closed. This basal part in the right 

 elytron (PI. XXII. fig. b), which is overlapped by that of the oppo- 

 site wing-case, forms in the centre an opake, smooth, horny plate of 

 irregular shape, and the margin projects as a quadrangular lobe with 

 much-thickened and raised horny edges. The same part of the left 

 elytron (PI. XXII. fig. rt) forms a thick horny lobe of quite different 

 shape : its edges are not raised, but the under surface is traversed by 

 a thick, horny rib, finely scored like a file, which comes in contact 

 with the raised edges of the corresponding lobe, and by the rapid 

 voluntary movement of the wings is scraped across them, producing 

 the very loud notes for which the insect is remarkable. This file- 

 like rib occupies the position of a very slender internal nervure 

 visible on the elytra of most of the insects of this family. The 

 genus is closely allied to Thliboscelus, Serville. 



Chloroccelus Tanana. (PL XXII. figs. 1, 2.) 



C. elongato-ovatus vel pyriformis, prasinus, alis pallidioribus : capite im- 



punctato : thorace transverse rugoso. Long, (alis clausis) 2" 3"'. 3 . 



The insect in life is wholly of a light-green colour, the membranous 

 wings being paler ; it fades after death, and becomes of a clingy olive- 

 yellow hue. The head is impunctate ; the forehead smooth and 

 shining; the frontal tubercle is excavated on its upper surface. 

 The prothorax is transversely and feebly rugose ; the central furrow 

 is strongly marked, continuing on each side to the inferior margin 

 of the pronotum. The abdomen is conical in shape, and has a 

 central, smooth, dorsal keel, which is interrupted by a large rounded 

 tubercle at the base of each segment. The elytra are of a thin, hard, 

 parchmenty nature, and slightly transparent; the basal lobes, as 

 before mentioned, are corneous and opake. 



The species is found in the middle part of the region of the Lower 

 Amazons, at Obydos and Santarem. It is met with most frequently 

 in the drier forests of the Guiana or north side of the river, from 

 Obydos to the lower part of the Trombetas, but it is not a common 

 insect anywhere. The natives call it Tanana, and admire it greatly 

 for its musical performances, keeping it, when they capture one, in 



vol. I. 2 M 



