478 PE. r. LEUTHNEE ON THE ODONTOLABINI. 



stripes on each side, as in the male, shoulder-angles acute ; front tibiae long and narrow 

 (like the male), with the terminal fork well developed, and three or four spines above 

 it on the outer side. 



Habitat. Malacca and Borneo. 



MeasMrements. 



Total length. Head. Mandibles. Prothorax. Elytra, 



millim. millim. millim. millim. miUim. 



cj. Normal (Borneo) 43 5-0 by 12 14 9 by 15 17-5 by 13 



Var. ceplmhtes (Borneo') . . 37 6-5 „ 9 13 7 „ 12-5 14-0 „ 11-5 



2 . (Malacca) 24 4-0 „ 7 3-2 6 „ 10-5 13-0 „ 10-5 



(Borneo) 28-5 5-0 „ 8 4-5 7 „ 12 16-0 „ 12 



This is so different from other species of Odontolahis that I have been obliged, like 

 Major Parry, to treat it as a separate section. It is distinguished by the striation of 

 the elytra in both sexes, the broad front tibiae of the male (resembling those of the 

 Chinese 0. platpiotus), and the pointed canthus. 



Very few specimens of this species are known (only three of each sex), and I examined 

 the types in Herr van Lansbergc's collection. 



There is a male from Borneo in Parry's collection (smaller than the others) in which 

 the head is very long, and the mandibles are strongly curved downwards, giving the 

 insect a totally different appearance. Prof. Westwood and Mr. C. O. Waterhouse are 

 inclined to consider it a new species ; but I have too few specimens to decide. How- 

 ever, I cannot consider the elongation of the head extraordinary in a telodont form. 

 The frontal crest is not raised here, but projects forwards (compare the enormously 

 developed frontal crest in Homoderus tnellyi, Deyrolle, Ann. Sci. Ent. France (4) iv. 

 p. 313, pi. iv. fig. 2 ; an extraordinary figure). 



The long deflexed mandibles are even more interesting and instructive than the 

 head ; they agree in structure with the smaller specimens of typical 0. striatus, but 

 instead of being flattened and horizontal, their hinder half is curved downwards at an 

 angle of 90°. The teeth at the base and tip are unaltered. 



These curved mandibles are remarkably like those of Chiasognathus, and plainly 

 indicate how these may have originated. Whether this form is distinct from 0. striattis, 

 or is only a monstrosity, the modification of the mandibles must always be regarded as 

 a remarkable instance of their plasticity, and of the correlation of the structure of the 

 head with that of the mandibles. I propose to call this form var. cephalotes. 



Other modifications of the male mandibles are at present unknown. 



