6 A. WATSON 



The key to genera and most of the keys to species are based on males alone. 

 There are two main reasons for this : firstly that the females of some species are 

 not yet known, and secondly that it is difficult or impossible at this stage to identify 

 the females of some groups of closely related species. 



Reference to a particular country or area in the paragraph on distribution in each 

 species description indicates that material from there has been identified during 

 the present study. 



DISTRIBUTION 



Generic distribution. (See Table i.) Most of the genera of Drepaninae which 

 occur in China have been recently revised, or are fairly well known in that their 

 taxonomy appears to be reasonably satisfactory and that identification of the 

 included species presents little difficulty. It has been possible, therefore, to show 

 in Table i the world distribution of these genera. Where genera have been revised 

 in the present paper, details of the distribution of all the included species have been 

 given in the Table ; the species of recently revised genera are listed in the Table 

 only if they are known to occur in China, but the full world distribution of each 

 genus is indicated. The species of other genera whose taxonomy is in an acceptable 

 state but which have not been revised recently or in this paper are listed fully. It 

 has been possible to give some idea in the Table of the distribution of the remaining 

 genera only when the generic placement of the included species is considered to be 

 probably correct. 



Nine of the 26 genera of Drepaninae present in China are either endemic to the 

 Indo-Chinese Subregion or have a high proportion of Indo-Chinese species with 

 incursions chiefly into the south-eastern limits of the Palaearctic Region and into 

 the Malayan Subregion. Tridrepana and Canucha extend to the Papuan Sub- 

 region, including the Solomons {Tridrepana). Palaeodrepana, Drepana and Cilix do 

 not occur east of the Indo-Chinese Subregion but extend westwards into Europe 

 (including Britain). Although some taxonomic reappraisal of Strepsigonia, Drape- 

 todes and Hyalospectra is needed, it seems likely that the former two will prove to be 

 chiefly Malayan, while the range of Hyalospectra will probably prove to be com- 

 parable with that of Canucha or Tridrepana. 



Callidrepana is unique in the Drepaninae in that it is represented both in the 

 Oriental Region and in the Ethiopian Region where three West African species are 

 known (see Watson, 1965). No comment can be made on the details of its Oriental 

 distribution until a generic revision has been carried out. 



Although the overall pattern of distribution may be distorted by the possibility 

 of differential extinction and the certainty that the areas involved have not been 

 uniformly covered by collectors, it seems reasonable to suppose that the apparent 

 high percentages of endemism in the Indo-Chinese Subregion represent the real 

 pattern of distribution. Thymistida, Didymana and Thymistadopsis, for example, 

 are unknown beyond the limits of the Indo-Chinese Subregion, while in Paralbara, 

 Agnidra, Betalbara, Nordstroemia, Deroca and Auzata the percentages of specific 

 endemism in this Subregion range from 60% in Betalbara to 83% in Auzata. This 



