THE ENTOMOLOGIST. 101 



belief the form with the flat prothorax. But further, from the 

 time of Fabricius to the present, cinerasceiis had always been 

 regarded as a doubtful species, the majority of authors having 

 treated it as only a variety of migratoria : the entomologists 

 from whose collections the Oxford specimens were derived 

 might have been of this opinion ; at all events until it was 

 shown that they recognized the existence of the two as 

 distinct species, the argument derived from their having 

 labelled specimens of cinerascens with the name migratoria 

 was far from conclusive. Finally, Linne's own description of 

 migratoria applied to the form commonly so called, and not 

 to the form with the arched prothorax. The differences 

 between the two had been pointed out by M. Brunner de 

 Wattenwyl (Ann. Soc. Ent. Belg. xi. 32) so clearly as to have 

 induced M. de Selys Longchamps to recognize Pachytylus 

 cinerascens as a species. The recent discussion had been 

 provoked by the appearance in this country of Acridium pere- 

 grinum, and had satisfactorily brought out the fact that, if 

 migratoria and cinerascens (= Christii, Curtis) were really 

 distinct species, both of them had occurred in Britain. [See 

 Mr. Walker's paper on these locusts in the ' Insect-Hunter's 

 Year-Book for 1869,' p. 16.] 



Larv(B of Argynnis Nlohe and Adippe. — Mr. Albert Miiller 

 mentioned that Meyer-Diir had pointed out certain differences 

 between the larvae of Argynnis Adippe and Niobe : in his 

 * Yerzeichniss der Schraetterlinge der Schweiz,' published in 

 1852, that author states that Argynnis Niobe in Switzerland 

 inhabits only the alpine and sub-alpine regions from 3000 — 

 6600 feet above the sea, and that its larva has in the full- 

 grown state a white dorsal stripe and flesh-coloured spines, 

 whilst A. Adippe is not found at a greater elevation than 

 3300 feet, and its larva has no white dorsal stripe, but a 

 pale reddish lateral stripe instead. Mr. Miiller argued, that 

 though the food-plants of both were various species of violet, 

 until this evidence was rebutted, or unless two different 

 larvae produced the same form of imago — unless there were 

 dimorphic larvae — Adippe and Niobe must be considered 

 distinct species, even though (which he did not admit) the 

 perfect butterflies were undistinguishable. Mr. Butler was 

 not acquainted with the larvae of Argynnis Adippe and Niobe, 

 and his suggestion that the two forms were one species was 



