371 
their describers, for no authorities are given. This matter is no 
doubt left to the check lists and other more special works. 
The first chapter deals with classification and nomenclature; 
the second with crabs, spiders, centipedes and other near relatives 
of the true insects, and the remaining nineteen with the six leg- 
ged insects or Hexapoda, each chapter being devoted to a sepa- 
rate order. This number of orders, as Prof. Comstock says, 
slightly exceeds that commonly adopted. The difference, as will 
be seen by the reader, results from dividing the Platyptera of 
recent classifications into four separate orders. Those adopted in 
the work are the following: 
RTORNORA ee Bristle-tails, Spring-tails. 
PPUMMERIDA 5 33+ 4s | May-flies. 
2s a hi re Sia Dragon-flies, 
PERCOPTERAS 2) 2.8 4" . . . Stone-flies. 
NSORPTER A C8 st Peck tee White-ants. 
WORRODENTIA® | .' 5 2 oy ges Procids and Book-lice. 
WEATLOPHAGAT Eo Sore oe Bird-lice. 
EUPLEXOPTERA®, 22 8 Earwigs. 
ORTHOPTERA. . . . . . . . Cockroaches, Crickets, Grasshoppers, etc. 
NNN Fe ary Thrips. 
RIERA Bugs, Lice, Alphids and others. 
WIROROPTEBA oo 5 SS Aphis-licris, Ant-licris and others. 
MOP TERA a Scorpion-flies, etc. 
SeiOHOPTERA 5 Caddice-flies. 
PRPIDPIBRA (ss se ee Moths and Butterflies. 
PRR Flies 
DEPHONAPTERA 2 Sy, Fleas 
CA MNTERA Go a Beetles. 
ELYMENOPTERA 6 ok SS Bees, Wasps, Ants and others. 
It is not supposed that this sequence is altogether a natural 
One, but the best that can be expressed in a linear series, and 
indeed, it does not make any difference whether, for instance, the 
Lepidoptera immediately precede or follow the Diptera. 
The greatest space is given to the chapter on Lepidoptera, 
which occupies 222 pages, and it is chiefly in this much collected 
order that changes of classification are noticed. They are based 
upon the venation of the wings; the character of the antenne, 
Vestiture, etc., not holding so prominent a position as in other sys- 
tems. This classification seems to be very good so far as clear- 
