350 Mr. A. R. Wallace on 



16. Thyca Descombes'i, Boisdiival. 

 Pieris Descombes'i, Bd. Sp. Gen. p. 465. 

 //a6.— N. India, Cochin-China (Coll. Wall., B. M.). 



17. Thi/ca zebuda, Hewitson. 



Pieris zcbuda, Hew. Ex. Butt. vol. iii. Pieris VII. f. 49, 50, $. 

 iP. Descombesii, Vol). Mon. Pier. p. 18. 

 //«&.— Celebes (Coll. Wall.). 



This species is very distinct from T. Descombesi, both in form 

 and colouration of both sexes. The male has the excessively 

 elongated wings so characteristic of the butterflies of Celebes. 



18. Thyca aruna, Boisduval, 



Pieris aruna, Bd. Sp. Gen. p. 466, $\ Hew. Ex. Butt, vol. ii. 



Pieris III. f. 20, 21, 22 ; Voll. Mon. Pier. p. 18. 

 P. bajura, Bd. Sp. Gen. p. 467,^ ? . 



Hab. — Waigiou, Batchian (Wall.) ; Obi (Voll.) ; New Guinea 

 (Voy. Coq.). 



This is perhaps the most beautiful and remarkable of all the 

 Pieridce, its two sexes presenting four totally distinct surfaces, all 

 finely coloured. 



19. Thyca harpahjce, Donovan. 



Papilio harpahjce, Don. Ins. N. Holl. pi. 18. Pieris harpahjce, 

 Godt. Enc. Meth. ix. p. 149; Bd. Sp, Gen. p. 458. 



ifa6.— Australia, Moreton Bay (Coll. W. W. Saunders, B. M.). 

 One of the handsomest of the Pieridce on the underside. 



20, Thyca nigrina, Fabricius. 



Papilio nigrina, Fab. Ent. Syst. III. i. p. 200. Pieris nigrina, 

 Sw. Zool. 111. 2 ser. pi. 69 ; Bd. Sp. Gen. p. 459. 

 ^fl6.— Australia (Coll. Wall., B. M.). 

 A common species in most parts of Australia. 



d. Syparete group. 



This extensive group may be subdivided according to details of 

 colouration. 



