6 
BRITISH BEETLES. 
The Myriapoda, as their name implies, are charac- 
terized by the possession of very numerous pairs of legs; 
the head is separate and distinct, and hears one pair of 
antennae ; the remaining segments are similar ; respira- 
tion is always effected by means of tracheae : the best- 
known members of the section are the Centipedes and 
Millepedes ; Dr. Claus (vol. i. p. 514) says that “ of 
all the Arthropoda the Myriapoda present the greater 
resemblance to the Annelids (among the Vermes), in 
the serial similarity of the segments, in the possession 
of an elongated, sometimes cylindrical, sometimes 
flattened body, and in the mode of locomotion. In 
fact they bear much the same relation to the Annelids 
that the Snakes do to the vermiform fishes amongst 
the Vertebrata.” 
The Insecta, by far the most numerous in species 
of any corresponding group throughout the animal 
kingdom, have in their perfect state six legs only, 
which are borne on the segments of the thorax, and 
are never attached to the abdomen ; some of these are 
occasionally abnormal or undeveloped, but never more 
than six are present ; the head, thorax, and abdomen 
are always distinct, a point which separates the section 
from the Arachnida (which, moreover, are furnished 
with eight legs), and from the Crustacea, moreover, 
they differ in always breathing atmospheric air through 
lateral spiracles by ramified tracheae (or air-pipes) ; a 
single pair of antennae is present, and two compound 
eyes usually composed of a large number of facets ; as 
a rule there are two pairs of membranous wings, 
which are borne by the two hinder segments of the 
thorax; these are sometimes only two in number, and 
are often entirely absent : in the Coleoptera the front 
