62 THE entomologist's record. 



M. affinn, M. subfavella, and F. ca.'<ta vary from -200111111. to 

 •203niixi. (except one F. casta •210mm.), F. intcrwediella •216mm.- 

 •227mm., i<^. bourrcUa ■240mm., 7'^. //«-»m;iiVrt. •182mm. --lOlmm. The 

 numbers are no doubt too small to found any strong conclusions upon. 

 In some degree these differences may be of value as specific characters, 

 as, for instance, in the case of F. bowerella ; but even in this instance 

 we find the rule holds that pectinations are of uniform length through- 

 out the genus, but that the length of antennal joints varies directly 

 with the size of the insect and inversely as the number of joints. 



Great reliance has been placed for distinguishing species on the 

 form, size, and colour of the Avings. Perhaps I unduly depreciate 

 these, my first impressions having been formed by attempting to verify 

 some distinct characters of this sort between the F. roboricolcUa, F. 

 nitidcUa, F. intcniicilidla, and M. crassiordla of our British collections, 

 working all the time as I now believe entirely within the limits of one 

 species. Apart from this, however, these characters are not very 

 valuable. As to colour, with the exception of the reticulate species, 

 and perchance of M. sHbfiavdla and M. ed ward sella [saxicolella ?), all the 

 species can be very black when fresh, but vary a good deal, and all 

 become a snuffy brown with age (especially if assisted by a little 

 damp). The form of the wing varies within the limits of a species to 

 some extent, and is very difficult to define as between different species. 

 In our English series unquestionably the apparent form of the wing is 

 much more dominated by various styles of setting than by any inherent 

 character. All the species have a certain amount of natural curvature 

 of the wings and of pleating or folding at the nervures, and the extent 

 to which these are straightened out by pressure and flat setting, or 

 exaggerated or altered by drooping or bad setting, much outweighs any 

 actual difference of form in the appearance of the insects. 



{To be continued.) 



British Dragonflies". 



By MALCOLM BUER, F.Z.S., F.E.S. 



It is with a real pleasure that we welcome Mr. Lucas' handsome 

 work on the dragonflies of Great Britain (and we observe the Channel 

 Islands are included), for, apart from the interest that the book evokes 

 by its own merit, it supplies a badly felt want in the literature of the 

 zoology of the British Islands. Hitherto the collector of dragonflies 

 has had to be satisfied with Harcourt-Bath's brief account, unless he 

 were able to consult the various periodicals dealing with the subject 

 in various languages, or McLachlan's purely scientific work. It 

 is this lack of a complete popular account of our Odonata that has 

 doubtless frightened many a beginner from the study of so interesting 

 a group. 



In the introduction, the author cites the latest census, quoting 

 W. F. Kirby's work of 1890, which enumerates 1800 species of known 

 recent Odonata, and suggests that, by future investigation, four times 

 this number might be discovered. Of these 1800 species, 39 are 

 British. There are further seven reputed species, always an irritating 



♦"British Dragonflies (Odonata)." By W. J. Lucas, B.A., F.E.S. [Upcott 

 Gill, 1900, 8vo., i)p. 1-356. With 27 coloured plates, and 57 figures in the text. 

 Price 31s. Gd.] 



