Mr. A. G. Butler on a new Butterjly. 103 



Pseudocmna histriata, G. O. Sars, " Om den aberr.ante Krebsdyrgruppe 



Cumaceer" (Vid. Selsk. Forhandl. 1864), p. 70. 

 ? Cyrianassa longicornis, Speiice Bate, Nat. Hist. Review, vol. v. 1858 



p. 203. 

 Cu7na bella, Meinert, "Crust. Isop. Amphip. et Decapoda Danise" 



(Naturhist. Tidssk. 3 R. 11 B. 1877), p. 179. 

 Cuma cercaria, Meinert, " Crust. Isop. Ampliip. et Decapoda Daniee " 



(Naturhist. Tidssk. 3 R. 12 B. 1880), p. 497. 

 Pseudoctima cercaria, G. 0. Sars, Middelliavets Cumaceer, 1879, p. 114, 



pis. xl.-xlii. 



This small species seems to be the most numerically abun- 

 dant of the Cumacea in the British seas. Its distribution is 

 as follows : — 



Belgium (Fan Beneden) -, Denmark {Meinert); Norway, 

 from Christiania to the Lofoten Islands {G. 0. Sars) ; Medi- 

 terranean, at Goletta, Messina, and Syracuse {G. 0. Sars). 



I can myself testify to the following localities : — Whitby, 

 Yorkshire, and Seaton Carew, County Durham [A. M. N.) ; 

 Sunderland {G. S. Brady); Cumbrae, Firth of Clyde {D. 

 Robertson) j Tarbert, Loch Fyne {Fishery Board Laboratory) ; 

 Naples {Zool. Stat.). 



It is a shallow- water form, found on a sandy bottom, 

 usually in 0-10 fathoms. Now first recorded as British. 



XII. — Description of a new Butterfly allied to Vanessa antiopa. 

 By Aethur G. Butler, 'F.L.S., F.Z.S., &c. 



For some years past I have held the view that what is 

 generally understood by the term species (that is to say, a 

 well-defined, distinct, and constant type, having no near allies) 

 is non-existent in the Lepidoptera, and that the nearest 

 approach to it in this order is a constant, though but slightly 

 differing, race or local form — that genera, in fact, consist 

 wholly of a gradational series of such forms. 



In opposition to this view certain " species " are cited as 

 isolated, or in no way united by existing intergrades to their 

 nearest allies, from which, moreover, they show such wide 

 differences that the existence of intergrades is regarded as 

 highly improbable. One of the best known and, at the same 

 time, widely distributed of these apparently isolated species is 

 Vanessa antiopa^ which, although slightly modified locally in 

 size and tint (the Central-American form being usually 

 smaller and the North-American larger and more heavily 

 speckled than the European type), yet has no described allies 



