1914-] 



F. H. GravEi^y : An Account of the Oriental Passalidae. 



193 



^Central tubercle present; supra-orbital tubercles and anterior pro- 

 longations of supra-orbital ridges absent ; pronotum not drawn out 

 into a bifid protuberance in front ; middle lower tooth of mandible 



2.1 (? always) immoveable 



Central tubercle absent, head smooth and concave; supra-orbital 

 tubercles and anterior prolongations of supra-orbital ridges present ; 

 pronotum drawn out into a bifid protuberance in front . . 

 Supra-orbital ridges not united to form a median tooth behind 

 central tubercle 



3.( Posterior ends of supra-orbital ridges curved inwards to form 

 together a median tooth situated immediately behind central tubercle ; 

 central tubercle elongated dorsally ; mesothorax smooth 

 Mentum with strong median keel ; mesosternum strongly punctured ; 

 abdominal sterna with at least a few hair-bearing punctures 



(Mentum not keeled ; mesosternum at most feebly punctured ; abdo- 

 minal sterna unpunctured 

 j Central tubercle unidentate or trideatate above 

 \ Central tubercle bidentate above 



/^Central tubercle never pedunculate, often without any posterior face, 

 anterior face never longer than dorsal, anterior end less highly elevated 



6}(. Central tubercle usually pedunculate; otherwise always with dis- 

 tinct posterior face, anterior face never shorter than dorsal, anterior 

 end much more highly elevated than posterior 



Front coxae almost contiguous; canthus extending about half way 

 across the eye; supra-orbital tubercles flattened, expanded at the 

 apex, truncate 



Front coxae widely separated ; canthus extending all the way across 

 the eye ; supra-orbital tubercles slender and pointed 



[Caiilifey, Kaup.] 



Comacupes,^ Kaup; pp. 

 204 & 267. 



[Tristorthns,^ Kuwert.] 



Taeniocerus, Kaup; 

 208 & 270. 



Aulacocycliis , Kaup; pp. 

 211 & 272. 



Auritiihis, Zang, p. 279. 



Cylindyocau,lns,V&\xm.'3iixe; 

 p. 279. 



The second section of the family appears to me to contain four Oriental sub- 

 families (in addition to the Tarquiniinae, see below, pp. 326-330) which may be dis- 

 tinguished thus: — 



/^Mentum without primary scars; secondary scars absent, or present 

 only as depressions or small grooves close to anterior margin^; outer 

 j tubercles of head always simple .. .. .. •• •• ..2. 



Mentum with primary scars, except when these are replaced by 

 more or less strongly developed secondary scars ^; outer tubercles of 

 ^head often complex . . . . . . . . . . - • . . 3. 



' Since preparing this key I have examined the type of Comaciipes minor, Heller, and specimens of 

 C /omcoWs, Kuw., from Borneo. These have proved to be, in several important characters, transi- 

 tional between the genera Comacnpes and Trisiorthus (see below, p. 267). 



^ I know of no really sharp distinction between these genera. The definition given here involves 

 the transference of Taeniocerus deyrollei, and with it I presume T. mastersi (I have seen specimens of 

 the latter determined by Zang, but not the original description), to the genus Aulacocydus. These 

 species appear to me to resemble A . rosenbergii more closely than they do any species of Taeniocerus. 



^ This distinction taken by itself is not altoo;ether a satisfactory one, for in one race of Ophrygon- 



