181)2.1 175 



whilst the wavy margins slope away in a curve to the dorsal aspect. 

 In ccBspititiella and fflaucicolella the notch is much shallower, and the 

 margins pass off horizontally ; in glaucicolella the notch is particularly 

 small and shallow, and occasionally is absent altogether. It is, perhaps, 

 scarcely necessary to add, in passing, that a tendency to vary within 

 certain limits is met with in these anatomical features just as in an}^ 

 other class of characters, without affecting in the one case more than 

 the other their general importance, d d are curious little pockets at 

 the outer corners of what we may call the vestibule of the genital 

 aperture ; they are very perfect in si/lvaticella, rudimentary in oltico- 

 leJla, C(Bsi)ititieUa and glaucicolella, and quite obsolete in alticolella. 

 e e appear also to be pockets, situated at the upper end of the external 

 portion of the canal leading to the bursa copulatrix ; they are present 

 in sylvaticella^ alticolella and murinipennella, but no trace of them, so 

 far as I can see, is to be found in ccespififiella and glaucicolella. It 

 will be noticed that sylvaticella and alticolella agree in the length of 

 the external portion (l) of the canal, which, in their case, reaches 

 back some distance beyond the inner edge of the segment, and also in 

 the possession of the inner pair of pockets (e e) ; ccespititiella and 

 glaucicolella, on the other hand, have short external canals, and want 

 the pockets e e ; whilst murinipennella holds an intermediate position, 

 having the short canal of the one and the inner pockets of the other. 



Sylvaticella, alticolella and murinipennella are so palpably dis- 

 tinct, that the figures may now be left to speak for themselves ; but 

 ccespititiella and glaucicolella do not stand on quite so good a footing, 

 for the parts exhibit something of the same closeness of relationship 

 which was found in the superficial characters of the moths and in 

 their cases and larvae, and some further remarks seem, therefore, 

 called for. In the first place, the external canal {h) is reduced in 

 glaucicolella to the very shortest dimensions. Next we shall observe 

 that the ridges running down from the corner of the " aperture " 

 reach quite to the notch in glaucicolella, but stop well short of it in 

 ccespititiella. Then these ridges are not nearly so prominent in glau- 

 cicolella (a point which the figure can only imperfectly show), and in 

 some specimens they even subside altogether about the middle of their 

 course, springing up again where the rudimentary pockets {d d) come 

 in. Another distinction occurs on the dorsal surface of the segment. 

 In ccespititiella a prominent dark brown ridge or backbone runs straight 

 down the middle from end to end ; the sole trace of it in the other is 

 a slight and inconspicuous thickening at the inner end, that only ex- 

 tends for about a fourth of the distance. The ovipositor or 9th 



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