vi PREFACE. 
ural orders of animals. The mode of arrangement, 
or classification, of these into larger groups is a 
matter of altogether secondary importance.” 
While the information herein contained is ex- 
pressed without technicality, the common names of 
orders and families are in every case followed by 
the scientific term, for the convenience of the in- 
structor or advanced student. So also as regards 
classification: the groups of animals are arranged 
in an order that represents the latest knowledge of 
the various forms that constitute them; thus, the 
plan of Professor Flower has been followed in the 
mammals; that of Dr. Gill in the fishes; and Pro- 
fessor Cope, in the batrachians and reptiles. The 
student is first presented with the lowest forms, as 
being the easiest understood, and so led to others 
more complex; this plan being considered the 
most philosophical and natural. 
The general characteristics of each branch or 
order are plainly defined, why and how they differ 
from preceding ones shown, and then examples are 
given of the individuals constituting the group that 
have been selected for their availability as repre- 
sentative forms, and for certain peculiarities that 
will be most readily impressed upon the memory. 
It is probably the experience of every teacher 
in zoélogy that little or no advancement can be 
made unless the student can be thoroughly inter- 
ested in the work, and to this end material has been 
