94 THE entomologist's kecord. 



there may be various considerations to the contrary. If the append- 

 ages are least specialised, so, one would expect the other characters of 

 the s]3ecies to have a more primitive aspect. It is difficult to say 

 whether this is so or not, nor does the geographical distribution give 

 much assistance in arriving at a conclusion. The most definite ground 

 for regarding this form as more primitive is the structure of the ventral 

 plate of the 10th abdominal segment. This plate used to be called the 

 *' scaphium," but as that structure is dorsal to the anus (and present 

 in comparative few families), it is obviously distinct from the 10th 

 abdominal sternite. It is this 10th abdominal sternite that assumes a 

 peculiar articulated structure in some groups, to which in those groups 

 the name " gnathus " seems appropriate. 



In the Hesperias this plate is solidly soldered to the dorsal portion 

 of the segment. In carthami it is a simple plate (armed with rough 

 points) forming, with the dorsal portion of the segment, a ring. 



3Chis structure is much the same in the cacaliae section of the 

 genus, in which also the clasps retain much of the same outlines as in 

 carthawi. In the alveiis section each side developes a specially formed 

 process, and the middle portion is iinchitinised, and the valves retain- 

 ing very similar structure, develope considerable enlargement of the 

 end of the valve (ventral) portion of the clasp. In the onopordi and 

 vialvae section there is more elaboration of these side portions of the 

 10th sternite, and the clasps are slightly modified. The five further 

 natural groups defined by Dr. Eeverdin differ a good deal from the 

 three already referred to, in the development of the clasps. These five 

 groups, all. more or less Eastern or Southern, except perhaps that of 

 sao, seem more nearly related together than to three more European 

 groups {cacaliae, alveiis, malvae), or four if we keep the cartlumii group 

 separate from that of cacaliae. 



To return, however, to the morphology. In the plate (PI. vi.) is a 

 photograph of the appendages of Hesperia carthami, and a diagram of 

 them for reference. 



a. The Tegmen ''tergite) ; h. The Saccus (sternite), with the connect- 

 ing lines of chitin form the ring of the 9th abdominal segment ; c. The 

 Uncus ; d. The connecting portion ; and e. the 10th sternite, forming 

 together the ring of the 10th abdominal segment. 



This 10th sternite had better be called simply the 10th sternite. Dr. 

 Reverdin has some remarks on it in the second volume of the Bulletin 

 of the Gieneva Societij, p. 143, in which he recognises that it is not the 

 " scaphium," and objects to calling it " gnathus," a name proposed for 

 it, only when articulated and moveable as in Scoparias, some Geo- 

 meters, etc. The term he proposes, " lateral apophj^ses of the uncus," 

 is not applicable to it in carthami, the uncus being the tergite and this 

 the sternite. It seems more correct in the alveiis group, where one 

 might contend that the apophyses were dorsal. " But the homology of 

 these apophyses in alveiis, etc., with the 10th sternite in carthauri, 

 cacaliae, etc., is too obvious to permit of this. They might probably 

 quite correctly be called " lateral apophyses of the 10th segment," or 

 "of the 10th sternite." 



In writing 10th segment one means of course 10th abdominal. 

 They are obviously not the sternite itself but processes of it. Though 

 Dr. Reverdin proposes the name of " lateral apophyses of the uncus," 

 he finishes the note in which he does so by saying that he adopts the 



