CXXX 
has been translated in the ‘ Annals and Magazine of Natural History’ 
for August. This insect, known here as the leaf-insect or brown 
Aphis of the maple, was discovered by Mr. 'Thornton in 1852, and 
described under the name of Phyllophorus testudinatus. In 1858 
Mr. Lane Clark changed the generic name to Chelymorpha, Phyllo- 
phorus having been already used. Chelymorpha, however, is in the 
same position, and M. Van der Hoeven therefore replaced it by Peri- 
phyllus. The insect is a minute form of Aphis, about one twenty- 
fifth of an inch in length, flat, and brown. It is characterised by 
“the extraordinary development and unusual appearance of the tegu- 
mentary system. Thus their surface is no longer furnished only with 
simple hairs, but also and principally with scaly transparent lamelle, 
more or less rounded or oblong, and traversed by divergent and rami- 
fied nervures, These lamelle occupy especially the anterior margin 
of the head, the first joint of the antenne (which is very stout and 
protuberant), the outer edge of the tibiz of the two anterior pairs of 
legs, and the lateral and posterior margins of the abdomen. Moreover 
the whole dorsal surface of the latter and of the last thoracic segment 
is covered with a design having the aspect of a mosaic, composed of 
hexagonal compartments, and which is not without analogy to the 
pattern formed by the scaly plates of the carapace of tortoises.”..... 
“ Another remarkable character of these abnormal individuals of 
Aphis Aceris is the rudimentary state of their generative apparatus. 
This is reduced to a few groups of small, pale, and scarcely visible 
cells, none of which arrives at maturity to become transformed into 
an embryo: and it retains this character as long as it is possible to 
observe the animal. The functions of nutrition, also, are performed 
in them in a very unenergetic manner; for from the moment of their 
birth until that at which we cease to observe them, they increase but 
little in size, attaining scarcely 1 millimétre. They undergo no 
change of skin, never acquire wings like the reproductive individuals, 
and their antenne always retain the five joints which they present in 
all young Aphides before the first moult. Nevertheless they possess 
a well-developed rostrum and an intestinal canal, the peristaltic con- 
tractions of which we have distinctly observed.” 
This curions Aphis turns out to be, not, as was at first supposed, 
the larva of a new species, but a special form of the well-known Aphis 
aceris. MM. Balbiani and Signoret consider that they have placed 
this remarkable fact beyond the possibility of doubt. 
The question naturally arose, What was the signification “ of these 
