398 DR. F. LEUTHNER ON THE ODONTOLABINI. 
But if we expected the same rule to apply to the males, we should be greatly deceived. 
It is approximately correct for the smallest males of the priodont form, but the larger the 
males the larger the front half of the body (consisting of prothorax, head, and mandibles) ; 
this is due to the relatively greater development of the mandibles; and thus the 
length of the front of the body very considerably exceeds that of the hinder portion’. 
The gradation will be most easily understood by comparing the accompanying table of 
measurements. The tip of the scutellum is the best point from which to take these 
measurements; the total length of the elytra has invariably been given in the systematic 
part of the paper (p. 445). 
Hinder half Front half Excess of 
of body. of body. front half. 
( 26 ; 26 = 0 
J 22 6 22, — 0 
#4 20 : 20 a 0 
lis : 19 = 0 
(22 : 24 = 2 | 
| * a ~ ‘ eee esea forms. 
| 25 32 2 7) 
| 25 34 = 9 
26 36 = 10 > Amphiodont. 
84 97 39 an 12 
es os = Zu | Mesodont. 
3 52 = 22 J 
| 34 56 = 22 
| 31 60 = 29 | Telodont. 
36 68 = ay 
{ shall reverse this order in treating of the divergences of the mandibles, beginning 
with the smallest and proceeding to larger and larger forms, because this is simpler, 
more natural and intelligible, and less difficult than the opposite method. 
In the smallest priodont forms of 0. alces, which most resemble the female in the 
shape of their mandibles, the mandibles are about as long as the head, and shaped like 
a broad knife. On the inside the teeth stand in an unbroken and peculiarly regular 
* When these investigations were undertaken in 1881, I selected a series of male specimens in which the 
increase was considerable, and arranged them in a regular series. But it must not be supposed that the man- 
dibles of the amphiodont forms are always larger than those of the priodont forms. There are also mesodont 
forms in which the individuals are not larger than the amphiodonts. In the course of my investigations I met 
with telodont forms also in which the total dimensions of the individuals were less than those of the mesodont 
or amphiodont forms. Comp. 0. castelnaudi (Pl. XCV. figs. 1, 2, 4) and O. brookeanus (figs. 18, 14, 15). 
