PREFACE. 



The Corylophidce were first formed into a separate family by Mr. Stephens in 

 1830. The few species which had been discovered previously to that date were 

 promiscuously distributed among various genera, to which they bore little or no 

 affinity. Starting from the small foundation thus laid by Mr. Stephens, the 

 Corylophida have gradually expanded and increased, until at the present time they 

 form a numerous and very natural group, anatomically, if not superficially, 

 congruous in itself, and abundantly distinct from any other family. 



The principal characters which distinguish the Corijlopliiche from other groups 

 consist in the form and peculiar folding of their antennae ; the great size of the 

 second joint of both the maxillary and the labial palpi ; the elongate and prominent 

 anterior coxae ; the minute size of the third joint of the tarsi ; and the great 

 enlargement of the first ventral segment ; to these may also be added the constant, 

 though less conspicuous, unilobed maxillge. 



The antennte are divided into three main portions, of which the apical portion 

 is composed of three joints, and the basal of two joints, except in OUgarihrum, in 

 which genus the basal portion consists of a single joint only ; the intermediate 

 portion, or funiculus, varies to a great extent in the number of its joints, and on 

 this variation the distinction between many closely allied genera chiefly depends, 

 and, moreover, the relative proportions of these joints is a specific character of the 

 utmost importance. When the antennae are withdrawn for the purpose of conceal- 

 ment, or rest, the apical portion is folded vertically back upon the funiculus, and in 

 this position is received into a hollow space, for it can scarcely be called a groove, 

 extending along the inner side of the eye as far as the anterior coxae. It is obvious, 

 therefore, that such a position renders it a matter of considerable difficulty to 

 extend the antennae sufficiently to obtain a correct view of the number and 

 proportions of the minute joints of the funiculus. But, however difficult it may be, 

 such an investigation is indispensable, for, as I have already said, on the number 

 and proportion of these joints both the generic and specific distinctions often 

 entirely depend. 



In this family, the organs of the mouth and proportions of the skeleton 

 of the under side, and also of the tarsi, are very characteristic, and generally 



