(exit) 
of the same species in the collection of the British Museum 
of Natural History. The larva bears the date :—‘‘ Durban, 
Nov. 3, 1906.” 
New British Letorrirus.—Dr. T. A. Cuapman showed 
several: specimens sent for exhibition by Mr. W. Purdey, 
including Leioptilus carphodactylus taken by him near Folke- 
stone. The species is new to the British list, although there 
is a specimen at South Kensington from the Stainton collec- 
tion, bred by Gregson and labelled carphodactylus, but placed 
amongst microdactylus, It is small for carphodactylus, and 
large for microdactylus, and, being a solitary specimen, not 
very typically marked, it is a question whether its label or 
its position be the more correct. The exhibition also contained 
some good varieties of Acalla cristana and a very dark ZL. 
tephradactylus, looking at first sight very like Z. scarodactylus. 
Errect oF ARTIFICIAL CONDITIONS ON SEASONALLY DrMor- 
pHic SpectEes.—Dr. F. A. Dixry exhibited specimens of Zera- 
colus achine, Cram., and Belenois severina, Cram., bred and 
captured at Salisbury, Mashonaland, by Mr. G. A. K. Marshall. 
He remarked that the exhibit, which was supplementary to 
that shown by him on December 5th (Proc. Ent. Soc. Lond., 
1906, p. civ), provided a further instalment of the results of 
Mr. Marshall’s valuable experiments on the effect of artificial 
conditions on seasonally dimorphic species. In the case of 
Teracolus achine, the exposure to conditions of moist heat in 
both larval and pupal stages had caused both sexes of a brood 
that should normally have emerged as the dry-season form, to 
assume the appearance of a wet-season generation. The same 
conditions operating in the larval stage alone had produced a 
close approximation to the same result ; while in specimens 
which had been similarly treated in the pupal stage only, little 
or no departure could be seen in the direction of the wet- 
season form. Specimens of both seasonal phases caught in 
the open were exhibited for comparison, and it was pointed 
out that these results with Zeracolus achine showed complete 
correspondence with those previously announced in the case of 
T. omphale, Godt. 
The behaviour of Belenois severina contrasted strongly with 
that of the two species of Teracolus, for whereas in the case of 
