MEANING OF SHAPES AND COLO UPS OF THE MEMBRACIDJE. 
283 
rest of the world in the amount and variety of mimetic resemblance in insects we see 
the outcome of a selective environment which may well have developed cryptic forms 
more strange and complex than any that are known elsewhere. But the possibility 
of mimetic likeness in Cyplonia and Bocydium should not be left out of account in 
the attempt to solve the problem. The fact that no undoubted explanation is forth¬ 
coming is by no means surprising ; and even when the living insects are studied 
under natural conditions it is quite likely that a solution may be long delayed. Every 
English entomologist has known from boyhood the “Comma’’ or “C” on the under¬ 
side of the wings of the butterfly Grapta C-album ; yet the explanation of a cryptic 
resemblance to the light seen through a semicircular crack in a weather-beaten 
fragment of dead leaf, although sufficiently obvious when once stated, was only given 
a few weeks ago ( Proc . Ent. Soc. Lond. for May 6, 1903). The writer hopes that 
Mr. Buckton’s figures of species of these two genera may induce naturalists in South 
America to make a special effort to solve this deeply interesting problem. The 
observer should keep a very open mind and not neglect effects produced hy com¬ 
munities of individuals of the same species, nor the possibility that a single Membracid 
surmounted by the branching appendages of its pronotum may resemble a combination 
of two quite different forms, such as an ant or spider attacking or carrying its 
insect prey. Figs. 4, 5, 6, and 7 on Plate XXXIII., and la on Plate XXXIV., should 
be looked at from this point of view. 
Passing to other genera, Poppca (Plate XXXIV.) presents structures similar to 
CypJtonia, but on a somewhat smaller scale. In Ceres a, StidocepJtala, Centrogonia , 
P/iacusa , Eurytea, Acutalis, Micrutalis , Trackytails, and Polyglypta (Plates XXXV.- 
XXXVIII.) we meet with shapes and colours, which generally appear to be explicable 
without difficulty as examples of protective (cryptic) resemblance to common plant 
structures. Species of the last-named genus (Plate XXXVIII.) appear to resemble 
elongated fruits or seeds, although the idea of mimicry of a Brenthid beetle should 
be tested by observation before being dismissed. Entylia , Publilia , Metheisa, and 
Oxygonici (Plates XXXIX. and XL.) are probably to be explained in the same way, 
in some cases resembling roughened bark or irregular fruits or seeds, in others 
perhaps buds. 
Parantonae dipteroides (W. W. Fowler), figured by Canon Fowler on Plate VII., 
Figs. 10 and 10#, of his monograph in the Biologia, is apparently a beautiful mimic, 
and the aculeate Hymenoptera of its sub-region (Central America) should be 
examined for possible models. Figured with wings outspread the superficial 
resemblance to a fly is undoubtedly strong, but the effect upon the contour of the 
dark coloured basal half of the depressed tegmina must be taken into account. 
Canon Fowler in stating (p. 102) that the species “has the appearance of a large 
