( XXV ) 



as in some genera of Stagbeetles (Odontolabis), A somewhat 

 similar interruption occurs in Dineutes. The facets in the 

 lower part of the eye are a trifle larger than in the upper 

 part (about 9 to 10). In many insects the reverse is the case, 

 the upper facets being larger than the lower, a notable case 

 being Anax. The lenses are circular in most cases where 

 they are very convex, as in Lathridius and Batocera. When 

 hexagonal they are often very irregular (the diagrams 

 exhibited showed parts of the eye of Hydrous and Sphinx). 

 The convexity of the lenses varies very greatly ; when 

 they are very convex the eye has a granular appearance, 

 but when not greater than the convexity of the eye itself, the 

 eye appears perfectly smooth {Bolbocems, &c.). The inter- 

 vening lines between the lenses are often beset with hairs, 

 sometimes very long and dense, as in the male honey-bee and 

 Trichophthahnus ; and the modification of the hairs into scales 

 which takes place on the body takes place on the eyes also, 

 the scales on the eyes of some beetles of the family Colydiidce 

 being very large, arranged in lines over the eye like tomb- 

 stones {Trachypholis). The eyes are placed on the top of the 

 head in Eciton and some other ants. A discussion ensued, 

 in which Mr. M'Lachlan, Mr. Verrall, Lord Walsingham, 

 Mr. Jacoby, Mr. Kirby, and others took part. 



Papers read. 



Mr. A. G. Butler communicated a paper entitled " Descrip- 

 tions of some new Lepidoptera-Heterocera in the collection 

 of the Honble. Walter de Bothschild." 



Mr. Butler also contributed a second paper entitled 

 " Synonymic Notes on the Moths of the earlier genera of 

 Noctuites." 



Dr. Sharp read a paper entitled "An Account of Prof. 

 Plateau's Experiments on the Vision of Insects." 



Lord Walsingham, Mr. Jacoby, Mr. White, and Mr. Water- 

 house took part in the discussion which ensued. 



PROC. ENT. SOC. LOND., III., 1889. 



