NOVITATES ZOOLOGICAE XXIV. 1917. 101 



specimens to be identical with Pyrenean individuals, while he remarks that 

 his Ain Khala $ was quite unlike the dull olive Pj'renean ?? in being bright red. 

 I unfortunately do not possess Philippeville specimens, but I can say that out 

 of the 464 Algerian didyma (of five races) I possess, 146 are ??, and that in all 

 cases they are either red or sandy-yellow, according to the subspecies, like the <?<?. 

 They only differ in being generally slightly paler. The Pyrenean ??, on the 

 other hand, vary from slate-grey suffused with rufous on costal half of hindwing, 

 to deep olivaceous slate colour suffused with gallstone yellow, and with rufous 

 hindwings ; while Sicilian ?$ (meridionalis) vary from mouse-grey with rufous 

 Ixindwings, to sandy rufous, the forewing slightly washed with olive. Algerian 

 cJc?, both of the western manreinnica form and the eastern nisseni form, have 

 the rufous colouring less brilliant and more of a sandy tone than either Spanish 

 occidentalis, Sicilian meridiomilis, or Pyrenean examples of didyma.'] 



42. Melitaea didyma mauretanica Oberth. 



Mditaea didyma forma mauretanica Obertliiir, Etud. Lipiil. Comp. Fasc. III. p. 243 (1909) (Algeria, 

 Spain). 



This form differs from my nisseni in its larger size, and in the postmedian 

 rufous band on the underside of the hindwing being farther away from the 

 antimedian band. The Tring series numbers 153 specimens. 



3 Hammam R'ihra, August 1915. Faroult. 

 145 JLisser Mines, June 1914, Faroult. 



1 Tlemcen, April 1914, W. P. and E. H. 



2 Titon Yaya, May 1915, Rotrou. 



2 ? (labelled Bou Saada, May 1912, Faroult, but evidently not from there). 



Miss Fountaine gives Teniet-el-Haad, June 1904. 



42a. Melitaea didyma nisseni Rothsch. 



Mditaea didyma ni.sse7ii Rothschild, Novit. Zool. vol. xx. p. 115 (1913) (Ain Draham). 

 149 Am Draham, July — August 1911, Faroult. 



426. Melitaea didyma interposita Rothsch. 



Melitaea didyma interposita Rothschild, Novit. Zool. vol. xx. p. 115 (1913) (Batna). 



This race of didyma is not only remarkable from its iiregular and widely 

 separated areas of occurrence ; but also for its subspecific characters ! For 

 while the cJcJ resemble more nearly d. mauretanica and never approach very 

 close to d. deserticola, the ?? are much nearer to d. deserticola, some being so 

 close to the latter on the upper surface that should the locality ticket be absent, 

 only the examination of the underside can determine which are which. 



16 Environs de Batna, Nelva. 



3 Lambessa, June 1912, Nelva. 



4 Oued Hamidou, June 1912, Faroult. 



The Tring series comprises 23 individuals. The British Museum possesses 

 8: 6 Meade- Waldo ; 2 Djurjura, July 1884, J. Merkl ex Elwes coll. Mr- 

 Meade- Waldo in his article gives the following data : Rabat, May 1901 ; Agurgur, 

 July 1901; Tsauritz Entsagauz, July 1901. 



Miss Fountaine records this form from Sebdou, .June — July 1904. 



