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REVIEWS AND BOOK NOTICES. 



The Genitalia of the Noctuidae, by F. N. Pierce, F.E.S. Liverpool : 



A. W. Duncan. Price 7/6. 



It Is not surprising that the volume before us has been awaited for 

 some time with considerable interest by entomologists ; for, although 

 books for students of the Lepidoptera are legion, we have never before in 

 Britain had one treating on the branch of the subject which Mr. Pierce has 

 made practically his own. True, we had many years ago two papers in 

 the ' Transactions of the Linnean Society ' dealing with the genitalia of 

 the Butterflies, by Mr. P. ?I. Gosse and Dr. F. Buchanan White respec- 

 tively, and still later in the United States of America some attention has 

 also been paid to the genitalia of the Noctuida^. But Mr. Pierce can fairly 

 claim that his book makes an innovation in the methods of study of this 

 branch of entomology so far as the lepidoptera are concerned. In some 

 other orders the great value of the genitalia in the determination and classi- 

 lication of species has long been appreciated, as instance the magnificent 

 work on the European Trichoptera by the late R. McLaclilan, F.R.S.. 

 In that order, indeed, and in the more obscure groups of the Neuroptera, 

 species are now determined almost entirely by the structure of the geni- 

 talia, as experience has proved that they are the only characters which 

 are different in practically every species, and at the same time constant in 

 themselves. 



We do not suppose that the genitalia will ever become as useful in the 

 determination or classification of the lepidoptera, because in the first place, 

 the vast majority of the species are so obviously different from each other, 

 even in marking, shape, wing and body characters, etc., that no possible 

 doubt about their distinctness or place in the group can exist ; and in the 

 second place, the genitalia do not appear to be by any means so infallible 

 a guide as in the other orders we have alluded to. For instance, Mr, 

 Pierce tells us (p. 27), that he can see no difference in the form of the 

 genitalia of Leucania pallens and L. favicolov, except that the latter is 

 larger. Then those of Xylophasia polyodon, X. sublustris, and A', lithoxylea 

 he says (p. 41) ' are wonderfully alike.' More recently, Mr. Pierce's exami- 

 nation of the genitalia of the tortrices Paedisca ncevarui and P. geminana 

 showed practically no difference. Yet the differences in other respects 

 in all these are so evident that probably every lepidopterist who knows 

 them in the field will continue to regard them as distinct species. 



On the other hand, it is clear that we have for years been regarding 

 as single species, some, which had the genitalia been examined, would long 

 ago have been separated into two, and in one instance, into as many as 

 four species ! This case occurs in the moth which, under the name of 

 HydrcBcia nictitans, has been supposed to be abundant everywhere, and 

 familiar to every collector. By the differences in the genitalia Mr. 

 Pierce easily makes the four species, nictitans, paliidis, lucens and cvina- 

 nensis out of it. It must in fairness be said here, however, that some 

 twenty years ago, Mr. J. W. Tuft separated to his own satisfaction, from 

 the habits, shape, and wing markings alone, paludis and lucens from 

 nictitans, a verdict in which, at the time, but few lepidopterists were willing 

 to follow him. Examination of the genitalia, too, has settled the specific 

 differences between Coremia fevriigata and C. unidentaria, between Nona- 

 gria arundineta and N. neurica, and between Retinia buolianii and R. 

 pinicolana, but of which few lepidopterists had previously any doubt. 

 On the other hand, Mr. Pierce's method seems to have settled the specific 

 identity of Noctiia conflua with A'', festiva, of Agrotis aqitilina with A. 

 tvitici, and Dianthcecici capsophila with D. carpophaga. 



The style of the book is attractive. In the Introduction, we have a 

 concise but clear account of the manipulation required for an examination 

 of the genitalia, followed by an explanation of the terms used in t'ne des- 

 criptions — some of them entirely new to the lepidopterists' vocabularv — 



1909 June I. 



