THE CANADIAN ENTOMOLOGIST. 127 



referred to, only two genera possess it, Catodaulis and Scclothrix, and for 

 which latter, in addition to the sheath-formed appendages of the meta- 

 sturnum, it forms the most important separative character from the nearest 

 related genus, Pyrgus (which see). 



A more or less deep and extensive excavation on the side of the first 

 abdominal segments (bauchgrube = abdominal cavity) may be observed 

 in the males of a great many genera of Hesperidae, although not always 

 easy to be recognized, as it is generally covered by long hair, which is 

 either spread smoothly or matted in confusion. It is most fully developed 

 in those genera whose males are provided with a costal-fold, particularly 

 in See/othrix, where the upper halt of the abdomen appears as if eaten 

 out. What seems most surprising is the apparent absence of it in some 

 males belonging to species which show it very distinctly. These speci- 

 mens being quite fresh and fully scaled, it is but natural to suspect that 

 the cavity is first found or becomes visible after coition and the evacuation 

 of the contents of their testicles. Nevertheless, the cavity actually exists 

 in other specimens that are in equally good condition, and exhibit it as 

 distinctly as the worn ones. A male of the American Eudamus Tityrus 

 F., which I impaled immediately after its exclusion from the pupa, shows 

 the cavity remarkably well developed. So there remains an enigma to be 

 solved by further research, and especially by the examination of fresh 

 specimens. The cavity seems, however, of little systematic value, on 

 account of its gradual appearance, which allows no sharp limits to be 

 drawn. 



The neuration of the wings has not been examined by me to the 

 extent required, nor with that accuracy which could only be attained by 

 denuding the wings, so as to enable me to decide, whether they furnish a 

 more solid foundation for a natural division of the Hesperidae than the 

 parts described above. This, I consider, the principal defect of my work. 

 For he who would undertake to establish a natural system of this group 

 could not possibly avoid performing that task. Neither have I examined 

 the anal appendages of the males, although 1 do not suppose that the 

 result of such an investigation would pay for the labor which it would 

 involve. 



The Hesperian Fauna of the European province (taken in the extent 

 ascribed to it in my Geographical Distribution of the Lepidoptera, etc., I., 

 p. 90, and II., p. 298) is by far poorer in species than any other of the 

 six great zoological " Regions " into which, according to Wallace's latest 



