502 Dr. A. G. Butler—A Revision 
T. acaste represents the wet-season phase, 7. halimede the 
intermediate, and J. celestis the dry-season phase of the 
species; but they are none of them confined to seasons, but 
occur (as is the case with other species in very arid countries) 
as mere coexistent variations. If the species could be trans- 
ferred to a variable climate, doubtless the varieties would 
become strictly seasonal forms, as is the case with other 
species of Teracolus. Our series of this species is very fine. 
84. Teracolus venosus. 
¢. Idmais venosa, Staudinger, Exot. Schmett. p. 43, pl. xxiii, (1885) ; 
@, Holland, Proc. U.S. Nat. Mus. vol. xviii. p. 759 (1896), 
Mombasa. 
This is a wet-season form somewhat resembling 7’. acaste, 
but entirely without the orange flush on the upper surface of 
the wings. It would not surprise me to find that in the dry 
season the male had a tint of orange and that the female 
resembled a washed-out 7’. celestis. However, this is mere 
conjecture. Mr. Marshall says that 7’. venosus comes closest 
to the halimede group. I would goa step further and say 
that it belongs to that group, for it differs in nothing but the 
absence of orange colouring. 
85. Teracolus heliocaustus. 
Teracolus heliocaustus, Butler, P. Z. 8. 1885, p. 768, pl. xlvii. figs. 8, 9. 
Somaliland. 
Intermediate between 7. halimede and T. pletone, being a 
little nearer to the latter, which it represents on the Somali 
coast. It is a dry-season form, varying much in the black 
markings of the upper surface. 
86. Teracolus pleione. 
Pontia pleione, Klug, Symb. Phys., Ins. pl. viii. figs. 7, 8 (1829). 
Idmais miriam, Felder, Reise der Nov., Lep. ii. p. 190, pl. xxvii. 
figs. 5, 4 (1865). 
Teracolus chrysomelis, Butler, Cist. Ent. i. p. 244 (1874). 
Idmais eucheria, Mabille, Bull. Soc. Ent. Fr. (5) ix. p. elxxiy (1879) ; 
Grand. Madag. pl. xi. fig. 5 (1887). 
White Nile and Arabia. 
T. miriam (=chrysomelis) is the dry-season phase of © 
T. pletone ; but in Arabia both forms occur as mere varieties 
simultaneously and emerge on the same day from the same 
batch of pups. It would be interesting to know whether the 
forms are seasonally constant on the White Nile. 
. 
me 
