524 
ZOOLOGICAL LITERATURE. 
dition, and also tlie general characters of the imago. He dis- 
cusses the phenomena of respiration in this insect and the bear- 
ing of his observations upon the subject of the respiration of 
insects in general,, and dwells particularly upon the nature of 
the metamorphoses of insects and their relation to questions of 
general zoology. 
Thysanura. 
Meinert publishes (Naturh. Tidsskr. ser. 3. Bd. hi. pp. 400- 
440) an important memoir on the family Campodece ( = lapygidce, 
Hal.), including the two genera Campodea (Westw.) and lapyx 
(Hal.). In his introductory observations he remarks upon the 
general classification of Insects in accordance with the structure 
of the mouth, and indicates some new views upon this subjeet 
derived from a consideration of the mode of attachment of the 
buccal organs to the head. Thus, in the mandibulate series, the 
mandibles and maxillae are articulated directly to the horny case 
of the cranium, and left freely outside of the mouth ; and 
Meinert remarks that, from this point of view, the Lepidoptera 
(Glossata) really belong to what we must still call the mandibu- 
late section, agreeing essentially in their mouth-structure with 
the Hymenoptera (Piezata) , to which in other respects they are 
so nearly allied. In the true sucking Insects, on the contrary, 
the mandibles and maxillae are retractile within the mouth, so 
that only their points are exposed; and the author indicates that, 
as a general rule, this difference of structure holds good also in 
the case of the larvae. The Thysanura present in some respects 
an intermediate form, the mandibles and maxillae being certainly 
organized for biting, but at the same time retractile within the 
mouth, and articulated, not to the cranium, but to a chitinous 
plate contained within its cavity. Meinert remarks further 
upon the larval characters permanently presented by the Thy- 
sanura, from which, however, he excludes the Lepismidm, regard- 
ing them as belonging to the Ulonata (Orthoptera) and as nearly 
approaching Blatta, The structure of the insects referred to the 
family is described in great detail by Meinert, and his descrip- 
tions are illustrated by numerous figures. He gives the follow- 
ing character of the CampodecB (1. c. p. 403) : — 
. Pedes cursorily tarsis distinctis, elongatis, biungulatis. Cor- 
pus elongatum, abdomine distincte lO-articulato. Spiracula 
perspicua, saltern terna. Abdominis laminae ventrales 7 priores 
appendiculatae. Cerci duo, e segmento decimo, ultimo, orientes. 
Antennae setaceae vel filiformes. 
Meinert insists particularly upon the presence of ten segments 
in the abdomen as supporting his view of the structure of the 
same part in Forficula. The two genera and their known species 
are characterized ; and Meinert remarks that Haliday, in charac- 
terizing lapyx y seems to have overlooked the chitinous plate 
