Eastern Pieridce. 383 



The occurrence of a species closely allied to T. polisma in 

 Mindanao, is another example of the zoological connexion of this 

 island and Celebes. T. illana marvellously resembles Pier'is 

 cijnis, although it differs in important structural characters, such 

 as the length of the discoidal cell, the structure of the anal valves, 

 and the form of the club of the antennae. I have little doubt but 

 that P. cegis of Felder is the female of this species. 



Prioneris, n. g. 



Antennae long, with a gradually thickened obconic club; head 

 small, forehead very hairy, with the blunt terminal joint of the 

 palpi not projecting much beyond it ; body stout, anal valves of 

 the male large, ovate, not tufted. 



Upper wings triangular^ the costa thickened and strongly toothed 

 throughout its entire length ; first and second subcostal nervules 

 arising near together at some distance before the end of the cell, 

 the second reaching the apex of the wing, the third of considera- 

 ble length, and forming a wide angle with the nervure ; the upper 

 radial as a branch of the subcostal, the upper disco-cellular spring- 

 ing obliquely from the subcostal as if part of the second radial, 

 and giving a peculiar arched form to the cell of the upper wings. 

 Cell of the hind wings two-thirds the length of the wing. 



This genus comprises a few large and fine Indian species, which 

 seem to have no direct affinity with the rest of the old genus 

 Picris. They are well characterized by the extraordinary serrated 

 costa, which in the larger species may be seen by the naked 

 eye. The arrangement of the nervures of the upper wing is also 

 very peculiar, and I am informed that Mr. Watson had already 

 noticed the absence of the cliaracteristic plumules from the wings 

 of the males of this group, although they exist in all the other 

 species of Picris. 



The species in several cases seem to mimic those of the genus 

 Thyca. P. theshjlls $ , on the underside, most strikingly imitates 

 T. belladonna, while the female resembles it on the upper side as 

 well ; P. s'lla is a perfect representation of T. eucharis ; P. 

 Cornelia is equally like T. singhapura ; and in all these cases the 

 species of Thyca are very abundant, and are weak, slow-flying 

 insects, while the mimicking species of Prioneris are rare, and in 

 all cases the pairs which resemble each other inhabit the same 

 district, and very often are known to come from the same 

 locality. 



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