150 SI'Ol.IA ZEYLANICA. 



THE PLUME-MOTHS OF CEYLON. 

 Part II.— The Orneodidae. 



By T. Bainbrigge Fletcher, R.N., F.E.S.. F.Z.S. 



(With 2 Plates and 8 Figures.) 



Introductory. 

 ^FlHE Orneodidae, easily recognized and sufficiently characterized 

 J- by the fact that both wings are cleft into six or more segments, 

 each ciliated on both sides, form an isolated group of Lepidoptera, 

 few in numbers and usually small in size, which may be considered 

 as nearly allied to the Pyralidae with some affinities to the Tineidse. 

 The point to be borne in mind is that the Orneodida? and Ptero- 

 phoridse, although both popularly included under the name of 



Plume-moths," do not appear to be at all closely allied to one 

 another. 



The norma] state of affairs in this group is a fission of each wing 

 into six segments, but in Ceylon we find the endemic genus Tris- 

 ccedecia with seven segments in the hindwing and six in the foi'ewing, 

 this unusual amount of fission forming a parallel to the analogous 

 case of Heptaloba amongst the Pterophoridse. It is worth y of note, 

 however, that the fissures in Trisccedecia do not extend more than 

 half way into the wing, whilst in Omeodes they reach practically to the 

 base itself ; this appears to indicate a very early divergence from the 

 primitive form, which we may imagine as having had shallow clefts, 

 or more anciently mere scallo pings, in the margin of each wing 

 between the terminations of the nervures. 



The Orneodid larva and pupa are extraordinarily different from 

 those of the Pterophoridse , and very closely resemble the forms 

 found in the Tineidae. The larva? of some, but not all, of the species 

 are peculiar in their habit of burrowing within the flower-stalks, 

 stems, or young shoots of the food plants, in which their presence 

 gives rise to gall-like excrescences. 



Classification. 



Hitherto four genera have been recognized in this group — Omeodes 

 Pcelia, Microschismus , and Trisccedecia — of which the first and last 

 only have been found in Ceylon, Pcelia being peculiar to South 

 America and Microschismus to South Africa. Microsch ismvs includes 

 two species, Pcelia and Trisccedecia are monotypical, but Omeodes 

 at present consists of some forty species, which have been recorded 

 from every part of the world. The constituent species of this 



