( weit) 
by the presence of the fine dusty particles and large pieces 
of leaf firmly attached to them. The gummy exudation, 
whatever its nature as a product may be, possesses a 
tenaciousness so extreme that none of the particles were 
in the least disturbed in the preserving process, although 
the glandular protuberances were considerably flattened by 
the rolling. Mr. White also stated that there are not any 
particular ‘“‘humps’’ upon certain segments, as had been 
stated in some descriptions, unless the small glands just 
noticed are intended, which is improbable; the skin, how- 
ever, is much wrinkled in the subspiracular region, forming 
an irregular and somewhat flattened fringe upon the sides of 
the. anterior segments, adding greatly to the general pro- 
tective resemblance of the larva to its food-plant. It was, 
moreover, interesting to find that this species, —so highly 
protected, as it is, that it requires long and patient searching 
to discover any larva whatever,—is much subject to the 
attack of enemies, as evidenced by the appearance of several 
parasitic flies, which Mr. White included in the exhibition, 
illustrating the fact that the more an organism is liable to 
danger the more will it develop, under natural selection, 
protective devices which will be proportionate to, and in 
direct relation with, the attacks of its foes, with the effect of 
becoming more specialised. With regard to the generic 
name, the insect had generally been referred to under the 
common term Geometra (of Linneus and Boisduval), while in 
Curtis’s ‘ British Entomology,’ 1830, vol. vii., it is figured 
(pl. 800) under the name Hipparchius smaragdarius ; but the 
consensus of opinion is in favour of that recognised on the 
Continent, viz., Phorodesma (Boisd.) smaragdaria (Fab.). 
Mr. Lewis exhibited about three hundred specimens of the 
genera Hetarius, Kr., and FHretmotes, Mars. The most 
remarkable of these was Heterius acutangulus, Lewis, dis- 
covered last year by Mr. J. J. Walker near Tangier, and 
recently taken by him at S. Roche, in Spain. The names of 
the other species exhibited are :—Heterius bedeli, Lewis, 
Hi. punctulatus, Lucas, H. comosellus, Fairmaire, H. pluri- 
striatus, Fairmaire, H. setulosus, Reitter, Hretmotes sociator, 
Fairmaire, from Algeria. Heterius acutangulus, Lewis, H. 
PROC. ENT. SOC. LOND., 111., 1888. E 
