in the Basin uf the Amazons. 263 



like the fore wiiig. Head, thorax, and abdomen all whitish. 

 Expanse of wings, 44 mm. 



One ? from Uananaa, north bank of R. Solomoens ; 

 R. Purus, Sept. 6th, 1874. 



48. PachyarcJies lustralis. 



Margarodes lustralis, Gn., Delt. & Pyr., 306, 324. 

 Marqaronia lustralis, Wlk., Cat. Lep. Het. B. M., 

 "xviii., 520. 



One <y from R. Javary, Dec. 8th, 1874. 



Walker seems to have confounded this species and 

 P. imitalis : of the seven examples of this latter men- 

 tioned by him, fom* are really P. lustralis. This latter 

 is larger than P. iuiitalis (38 mm. as compared with 

 28 mm.), and has glaucous-green fore wings, while those 

 of P. imitalis are milk-white. 



49. Pachyarches aurocostalis. 



Margarodes aurocostalis, Gn., Delt. & Pyr., 305, 322. 

 ? Geometra costata. Fab., E. S., iii., 2, 287. 



One (^ from Boa Ventura, R. Jutahi, Jan. 24th, 1875. 



Guenee's type was from Guadaloupe ; there are no 

 examples in the British Museum Collection. The present 

 specimen, which is in perfect condition, has the fore 

 wing shot with shining grey, especially along the inner 

 margin (where it is interrupted by a white spot), and 

 along the hind margin and fringes of both wings ; a 

 small dark spot at the end of the cell ; the marginal 

 points of both wings black and distinct. With these 

 exceptions the example answers well to Guenee's de- 

 scription. 



50. Hyalitis bajulalis. 



Hyalitis bajulalis, Gn., Delt. & Pyr., 291, 294. 



Seven examples. Five males from R. Javary, Dec. 

 2nd and 4th ; one male from R. Purus, Sept. 13th, 1874 ; 

 and one $ from Serpa, Feb. 13th, 1875. 



Guenee's types, a male and female, were from Cayenne. 



T 2 



