440 DE. F. LEUTHNER OX THE ODONTOLABINI. 



smooth ; prosternal and mesostemal processes but slightly developed (fig. 4 a) ; elytra 

 olive-brown, finely punctured, and thinly clothed with browu hair; front tibise with 

 two spines above the terminal fork. 



Mandibles. 



1 & 3. Forma telodonta and Forma priodonta. — At present unknown. 



2. Forma amphiodonta. — Mandibles longer than the head, three-cornered, upper side 

 flattened, distinctly punctured, long and straight, with five teeth at the tip, and two or 

 three at the base. 



Female. Quite hairless, very like that of the preceding species, but more slender ; 

 prothorax with two, or often three, lateral spines like the male ; prosternal process 

 flattened; elytra long and narrow; front tibiae narrow, with three or four spines above 

 the terminal fork. 



Number of specimens examined : fifty-four males, and twenty-seven females, in the 

 collections of Oxford, Leyden, Amsterdam, Paris, and London {Bates and Parry). 



Habitat. Sirdang (Sumatra) and Sarawak (Borneo). 



Elytra. 



millim. 

 29 by 20 

 28 „ 20 

 26 „ 19'5 



25 „ 19 



26 „ 19-5 



I diligently sought for as many specimens as possible, but was unable to meet witli 

 either the telodont or the priodont form. 



Although 0. gracilis ( d ) from Nias appears to be very distinct from Bornean 

 specimens of 0. dalmani, in wliich the whole body is hairy, it is impossible to draw a 

 sharp line between Bornean and large Sumatran specimens, either in one sex or the 

 other. The Leyden Museum possesses an amphiodont male (G4 millim. in length), 

 without locality, which appears to be intermediate between tlie two forms. Its upper 

 surface is smooth, and very sparsely hairy. The prosternal and mesosternal processes 

 are strongly developed ; and the under-surface of the prothorax is longitudinally 

 striped on the sides as in 0. gracilis. The short rounded mandibles are compressed, 

 and much resemble those of 0. siva, but there are three basal teeth (not two), and 

 five apical ones ; the spine behind the eyes projects slightly forward ; and the front 

 tibife have two or three spines above the terminal fork. 



Total length 64 millim., head 11 by 20, prothorax 13 by 25, elytra 32 by 24^, 

 mandibles 15. 



