THE GENUS ACRIDIUM. 81 



But Jachontov (in Russia) and Oberthvir (in France) bring in 

 outside considerations, quite separate from those that characterise 

 coretaa, Ochs., as an aberration of /','. an/iades, Pall., and which 

 suggest that tbey are not discussing coreius, Ochs., at all. Jachontov 

 stales that the insect he is talking about "a L. mijiades, Pall., 

 differt non solum 'alls subtus uiaculis rufis nullis' (quod insigne 

 apud Staudinger and Rebel affertur) vel subnullis, sed etiam uiagni- 

 tudine paulo luajore, codicula alarum posticarum duplo breviore, 

 pagina superiore $ Ifetius cterulea, tenerius nigro-marginala, punc- 

 torum seriei externa^ dispositione, qua L. coratas cum L. fischeri 

 congruit." 



Now none of these particulars came witbin the purview of Hiibner 

 or Ochseubeimer, nor have tbey anyihing to do with the insect we know 

 as alcetas, }Ih. = coretas, Ochs., per se. One asks then, are these 

 characters within the variational limits of argiades? Does aniiades 

 vary in wing-expanse, in the size of the tail of the bindwinfts, in the 

 tint of the forewings, in the width of the marginal band, in the 

 size and direction of the spots on the undert^ide ? We have a good 

 deal of information on this point, which we hope later to publish in 

 its proper place in our Natural History of the British Lejridoptera. 

 In the meantime accumulated evidence from all lepidopterists who 

 collect European butterflies would be very useful. 



Obertbiir makes the following points (not dealt with by Hiibner or 

 Ochsenheinier) of the Pyrenean form, which he considers caretas. An 

 entirely black upperside in the ? , and the tail sometimes wanting. 

 One asks whether these characters also vary within the specific limits 

 of arj/iades. 



We want definitions to know exactly what we are talking about. 

 But it appears beyond question that whatever insects Jachontov and 

 Obertbiir are dealing with, there can be little doubt that contas, 

 Ochs., as we at present know it, is an aberration of ari/iades. It would be 

 interesting if other lepidopterists who believe the name art/iades is 

 standing for more than one species, viz. (1), an ab. of arijiades, (2) a 

 distinct species, would give descriptions and figure the ancillary 

 appendages side by side with those of undoubted anjiades. 



A somewhat humorous point comes out of this superficial treat- 

 ment. If the shortness of the tail of the hindwings really is a 

 character in the so-called specific form noticed by Jachontov, it would 

 appear that the character belon^^s to aryiades, Pall., for Pallas in 

 his original description says " alls que subcaudatis (ut Pai>ilio rtibi) " 

 which is, one suspects, something of what Jachontov means by his 

 reference. But the fringe-" tail " of anjiades is a somewhat shaky 

 characteristic. When will our students of variation, however, take 

 the trouble to learn the alphabet of their study and make a point of 

 working from original descriptions? "There is no royal road to 

 mathematics" nor to the study of variation. 



The Genus Acridium.-' 



By MALCOLM BURR, B.A., F.E.S., F.L.S. 

 In working out collections of grasshoppers and locusts, especially 



* " Sur le Genre Acridium : contribution a I'otiide du ^enre Acriilinin, Serville, 

 de la fiimille des Acridiens, Insectes Orthopt^res, avec descriptions d'esp^ces 

 nouvelles," par A. Finot. [Annales de la Socift6 entomologique de France, 

 vol. Ixxvi (1907).] 



