1897.] OS THE CLASSIFICATION OF THE THXBIDID.E. 603- 



and possibly Phanempleuron, approached more closely to Ceratodus 

 than did Dlpterns and its allies. The last-mentioned Dipnoi, on 

 the contrary, seemed to represent a divergent and terminal branch 

 ot" the Dipnoan stem and to include the most highly specialized 

 examples of the group. 



This memoir will be published entire in the Society's ' Trans- 

 actions.' 



The following papers were read : — 



1. On the Classification of the Thyrididos — a Family of the 

 Lepidoptera Phalseuse. By Sir George F. Hampson, 

 Bart., F.Z.S. 



[Eeceived April 8, 1897.] 



The Thyrididce, of which a classification is here given, is a small 

 family of Lepidoptera closely related to the ancestral stock of the 

 Fyralidce, in which family they are most nearly allied to the 

 Indian Simcethistis and to two Australian species, asuridia, Butl., 

 and maynifica, Meyr., for which a genus requires to be made. 

 Most of the genera have veins 2 to 11 of the fore wing arising 

 from the cell, and vein 8 of the hind wing approximated to 7 at 

 or beyond the end of the cell, not anastomosing with 7 as in the 

 majorit}' of the Fyralidce. These characters show a very gene- 

 ralized type of structure, but as specialized developments we 

 have the abortion of the maxillary palpi and of the vein in the 

 submedian fold of the hind wing, which prevents their being 

 regarded as the ancestors of the Fyralidce, in all of which the 

 latter character is retained and also the former in all except a 

 specialized subfamily, the Chrysaugince. 



From the Thyrididce were derived the Drepanidce, closely related 

 to them and differing principally in the more complicated neuration 

 of the subcostal veins of the fore wing and in vein 1 a of the hind 

 wing being absent or short, these again giving rise to the small 

 Oriental day-flying family Calliclididce ; the whole group of families, 

 which includes also the Fteroijhoridce and Orneodid<F, having sprung 

 from the Tineid stock near the ancestors of the Sesiadce and 

 Zygcenidce. 



The Thyrididce are almost entirely confined to the Tropical zone ; 

 the genus Thyris itself is Palsearctic and Nearctic, but of the rest 

 of the family only two or three species spread into the Southern 

 States, a few more to Japan and N. Asia, and one to New Zealand. 

 The ancestral form of the family would have short porrect 

 palpi, all the veins of the fore wing from the cell, the hind 

 wing with vein 5 from the middle of the discocellulars and vein 8 

 free ; with such a form Morova conforms except that veins 8 and 

 9 of the fore wing are stalked. From this ancestral type have 

 developed forms of abnormal shape and appearance culminatino- 

 in Hcpcdiodes — forms with the subcostal neuration of the fore 

 wing modified in various ways, such as Beguma, Flagiosella, and 

 Fycnosoma, and forms with the discocellulars aborted, such as 

 Glanycus and Thyris. 



