RHYNCHOPHOBA. 105 



The following table shows the method of subdivision as given by 

 Leconte and Horn (1. c. p. xv.): it rests chiefly on the structure of the 

 pygidium, and the presence or absence of a peculiar ridge on the inner 

 surface of the elytra, into which the ascending margin of the metathoracic 

 epimera and ventral segments fit. 



I. Pygidium alike in the male and female, formed of a 

 single piece ; elytra without lateral fold on inner 



surface HAPLOGASTRA. 



i. Labrum distinct, mandibles flat, simple . . . . RHINOMACEBID.E. 

 ii. Labruin wanting. 



1. Mundibles flat, toothed on outer and inner edge . RHYXCHITID^:. 



2. Mandibles stout, pincer-shaped ATTELABID.E. 



II. P\gidium unlike in the male and female, formed of 

 two distinct segments ; elytra with an acute lateral fold 



on the inner surface ALLOGASTRA. 



i. Antennae witli annulated or solid club. 



1. Tarsi narrow, setose ; prosternum excavated . . (B FBSOPID..) 



2. Tarsi dilated, usually with a brush of hair 



beneath. 



A. Mandibles with deciduous tip, bearing a scar OTIOBBHYXCHID.E. 



B. Mandibles without scar, usually pincer-shaped CUBCTT LIOSID^:. 

 ii. Antennae with ten or eleven distinct joints . . . (BBENTHID,E.) 



III. Pygidium alike in the male and female, formed of a 

 single piece ; elytra with a distinct lateral fold on the 



inner surface ." HETEROGASTRA. 



i. Pygidium vertical or declivous. 



1. Antennae geniculate, clubbed ; labrum wanting ; 



last spiracle covered by ventral segments . . . CALANOBiDa:. 



2. Antennae straight; labrum distinct; last spiracle 

 not covered by ventral segments; pygidium deeply 



notched to receive sutural apex of elytra . . . ANTHBIBID.E. 

 ii. Pygidium horizontal, smaller. 



1. Antennae geniculate, clubbed ; terminal edge of 



last ventral segment acute, surrounding the last 



dorsal; tibiae generally compressed and serrate SCOLYTID.E. 



2. Antennae straight, with annulated club ; maxillae 



\ery large, palpi and ligula feeble APIONID.E. 



Although the table is of considerable value, yet it can hardly be 

 regarded as altogether accurate ; as pointed out by Bedel, the genus 

 Apion, which is placed in the Heterogastra, has the pygidium in the 

 male composed of two segments as in the Allogastra, and some of the 

 Haplogastra, as, for instance, Byctisciis, have the lateral fold on the 

 inner surface of the elytra as fully developed as in the Allogastra, and 

 doubtless several other exceptions could easily be discovered. 



In discussing the question of the Classification of the Rhynchophora 

 we can hardly omit some reference to the work of Lindeman (Bull. 

 Mosc. LI., 1876, pp. 159, &c.); this author separates the families on 

 the presence or absence of a mechanical digestive apparatus in the 

 gizzard ; this is wanting in the Anthribidae, Bruchidae, Rhinomaceridce, 

 Attelabidae and Apionidae, but is possessed by the remaining tribes ; 

 it ordinarily consists of longer or shorter plates (Kauplatte), (usually 



