1;4 Memoirs of the Indian Museum. [Vol. VU, 



distinct ; secondly, a species which Zang (1905c, p. 226) has shown not to be the Malaysian 

 species for which Kuwert took it, but probably also a form of tricuspis ; and thirdly, a 

 species felderi, Stoliczka, from Amboina and Ceram, with a simply pointed central tubercle 

 and long antenna! leaflets like those of the Moluccan species of Aulacocyclus. The genus 

 Tristorihus is thus seen to consist only of a New Caledonian species (or group of species) 

 and a Moluccan species, allied respectively to different groups of the genus Aulacocyclus, \tl 

 which I therefore propose to place them. 



The genera of Aulacocyclinae may now be redefined thus : — 

 f The middle lower tooth fixed ; the aedagus composed of two 

 consecutive pieces, the tegmen and median lobe j 1 the central 

 tubercle always present near the middle of the upper surface 

 of the head . . . . . . . . . . . . . . 2._ 



The middle lower tooth moveable ; the aedagus composed of 

 three consecutive pieces, the tegmen being composed of a basal 

 piece and lateral lobes ; the central tubercle absent or occupy- 

 ing the whole of the antero-median part of the upper surface 

 of the head . „ . . . . . . . . . . . . 4. 



The mentum with a strong median keel . . . . Comacupes, p. 14. 



The mentum not keeled . . . . . . . . . . . . 3. 



The scars on the pronotum large, more or less ramified 

 or S-shaped ; the central tubercle broad and low, never 

 pedunculate (Oriental forms only) . . . . . . Taeniocerus, p. 16. 



The scars on the pronotum not very large, crescentic or circular ; 

 the central tubercle taller, usually pedunculate (mostly not 

 Oriental) . . . . . . . . . . Avlacocyclus, p. 17. 



The central tubercle present, often very strongly elevated, its 

 apex fused with the anterior margin of the head ; the elytra 

 separate . . . . . . . . . . Ceracupes, p. 21. 



The central tubercle absent ; the elytra united .. .. Cylindrocaidus, p. 21. 



Genus COMACUPES, Kaup, 1871,'p. 17. 

 Type, Passalus cylindraceus, Perty, 1831, p. 36, fig. 3. 



Comacupes cylindraceus (Perty). 



Passalus cylindraceus, Perty, 1831, p. 36, fig. 3. 



Comacupes cylindraceus, Gravely, 1914c, p. 207, text-fig. 2, pi. xi, figs. 5-6a. 



Specimens from the Malay Peninsula (Pahang), Singapore, North Nias (many from Hili 

 Madjedja and one from G. Madjeja), Middle Nias (Dyma and Kalim Bungo), Sumatra 

 (Bedagei interior, ca. 600 ft.), Java and Borneo (Mt. Marapok). Mr. C. Holman-Hunt 

 has sent me for examination a specimen from Rawang in the Malay Peninsula. Length 

 24-5-27-5 mm. 



1 These names for parts of the mnle genital tube are those adopted by Sharp and Muir (1912, pp. 481-483 and 

 484-485). 



