GENUS CASTNIA AND SOME ALLIED GROUPS. 165 



so that the scaly covering of the fore wings could he easily removed or raised, showing 

 the markings of the wings of the future moth of a diminished size (PI. XXVIII. fig. 3). 



The classification of the species of the genus Castnia has not hitherto heen successful, 

 owing to the imperfect examination of the minute specific details of structure of many 

 of the species; nor can I hope to hare heen more fortunate than my predecessors. 

 Dalman, who described seventeen species of the genus in his memoir in the Swedish 

 Academy's Transactions, remarked in his introduction that C. linus differed from the rest 

 in its more elongated and partially hyaline wings and abdomen, longer than the wings, 

 adding, — " An proprium etsi propinquum genus has discrepantise indicant ? " In his 

 list of the species at the end of his paper he places O. cronus in a separate second section, 

 and C. linus in a third, without any characters ; and his description of the former of 

 these two species is confined to its colour and markings. 



Mr. G. R. Gray, in his memoir in the Entomological Society's ' Transactions,' proposed 

 to divide the species into five sections : — 



1. Those with the palpi very long, closely applied to the head, and covered with short 

 scales. The fore wings are subtriangular, thickly covered with scales, with the exterior 

 margin straight or slightly rounded ; the lower wings beneath with one guide (or bristle 

 working in the socket at the base of the fore wing). C. cyparissias, licus, evalthe, 

 Fonscolotnbei, &c. (pi. xiii. fig. 1). 



2. Those with the fore wings elongate, triangular. The hind wings are expanded, 

 with the posterior margin somewhat truncated : C. ardalus, palatinus. 



3. Those with the palpi short, reaching halfway towards the base of the antennas, and 

 covered with long scales ; the fore wings covered with small scales, with the exterior 

 margin rounded. The outer margin of all prominently fringed with long scales : C. 

 ffiibneri (pi. xiii. fig. 2). 



4. Those with the wings covered with minute scales, partly diaphanous ; the fore pair 

 with the exterior margin rounded ; similar also in the hind pair, with three wing-guides : 

 C. cochrus, linus, and acrceoides. 



5. Those with the antennas similar to the others, but the hook at the apex is formed 

 of large scales. The head of the male is very broad, and the eyes are much larger than 

 in the female. All the wings have the outer margin rounded, with a narrow fringe of 

 small scales, and with four wing-guides. The sexes differ much in colour : C. nicon 

 (pi. xiii. fig. 3), thais. 



The plate accompanying the memoir of Gray gives the veining of the upper and lower 



wings, the clava of the antennas, and the palpi of the 1st, 3rd, and 5th of these groups. 



Mr. P. Walker, in his Catalogue of the Lepidoptera Heterocera, Part I., neglected the 



various excellent characters pointed out by Mr. G. E-. Gray, and divided the species 



simply in accordance with the form of the wings, thus : — 



Div. 1. Body thick. 



Subdiv. 1. Fore wings slightly angular at the tips; hind wings rounded. 



Sect. 1. Wings very broad. C. dadalus, Latreillii, atymnius, cochrus, &c. (16 species). 

 -Sect. 2. "Wings rather narrower; fore wings longer. C. satrapes, therapon, ardalus {Brecourtii) , 

 invaria {icarus, var.) , inca, palatinus, subvaria {phalaris) . 



z2 



