144 Mr. J.8. Baly on the Classification of the Eumolpide. 
and indeed, although their facies is so distinct that (with one or 
two exceptions) the merest tyro in entomology could easily separate 
the two families, still I know not any one set of characters by which 
they can be rigidly divided from each other. Lacordaire, in his 
‘Mon. des Phytoph.’ tom. i. p. 1, mentions the bilobed third joint 
of the tarsus, taken in connexion with the toothed claw, as being 
the distinctive mark of the Eumolpide ; these characters, however, 
exist conjointly in Gastrophysa and several allied genera of Chryso- 
melide. Dr. Stal (Mon. des Chrysom. de ’Amér. p. 4) points out 
the more or less globular anterior cox in the Eumolpide in contra- 
distinction to the transverse anterior cox of the true Chrysomelids 
as separating the two groups. I myself, about the same time 
(Journ. of Entom. tom. i. p. 24), mentioned another character by 
which I thought the two groups might be separated, viz. the form of 
the anterior episternum *, this part of the body being always trans- 
verse in the Chrysomelide, and more or less quadrate or wedge- 
shaped in the Eumolpide ; but on close investigation I find that these 
two characters, viz. the forms of the cox and episterna, mutually 
depend on each other: thus with a transverse coxa the episternum is 
confined to the upper edge of the cotyloid cavity, and is necessarily 
transverse ; with a subglobular coxa, on the other hand, the epi- 
sternum is produced downwards, halfway along the outer border of 
the coxa, forming the anterior half of the outer as well as the whole 
of the upper edge of the cotyloid cavity. These distinctive characters 
have a much wider application than those mentioned by Lacor- 
daire, the only exception, as far as my present knowledge extends, 
being in the genus Huryope, which, although a true Eumolpidous 
form, and agreeing in all other characters with that group, possesses 
the episterna and coxee of a Chrysomelidous insect, thus appearing 
to unite the two families. 
The Eumolpide may be characterized thus :— 
Body rotundate, oblong or elongate, more or less cylindrical, generally 
glabrous above, at other times clothed with hairs or scales, which are 
usually adpressed. Head either moderately exserted or more or less 
deeply buried in the anterior cavity of the thorax; face perpendicular ; 
antennze simple, rarely shorter than the head and thorax, seldom ex- 
ceeding the body in length, filiform or subfiliform, rarely incrassate ; 
eyes notched or entire, distant ; mentum short, transverse, frequently 
bent upwards into the head, its anterior margin usually emarginate, 
ligula corneous ; terminal joints of palpi generally ovate, rarely clavate. 
* This part was formerly named by me the antero-lateral process of the ante- 
pectus. 
