I9I4-] 



F. H. Gravely : An Account of the Oriental Passalidae. 



3< 



have seen in each species has been carefully noted in the descriptions given i 

 more extended account of the genus (above pp. 228-240). 



Upper tooth of both mandibles distinct ; lowest terminal 

 tooth of right mandible rudimentary or absent; anterior lower 

 tooth of right mandible minute or absent, that of left mandible 

 j always very large 

 Upper tooth of both mandibles obsolete ; lowest terminal tooth 

 of both mandibles normal ; anterior lower tooth of right man- 

 dible well developed, that of left side not always abnormally 

 large 



No convexity of upper margin of left mandible, behind base of 

 hinder margin of simple or bifid upper tooth ; this margin con- 

 cave, straight, or convex the whole way from tip of tooth 

 2( backwards (see figs. 26a, 27a, 28&, 29) 



Upper tooth of left mandible always simple, set in a hollow in 

 front of a convexity of the upper margin from which it is dis- 

 , tinctly separated at base (see fig. 25a, pi. xii; & 4C, p. 234) 

 Upper tooth of left mandible very variable ; a small denticle 

 sometimes present below the apex (figs. 28a, 32), but the apex 

 itself not bifid (figs. 26«, 27a, 28, 29, 30, 32, 33) except some- 

 times in species in which the anterior angles of the head are 

 very distinctly prolonged forwards (fig. 286) 

 Anterior angles of the head obtuse, never prolonged forwards ; 

 apex of upper tooth of left mandible always more or less dis- 

 tinctly bifid in unworn specimens (see especially fig. 31) 

 Right outer tubercle simple, elongate, acute (figs. 26, 32, 

 33) ; anterior angles of head truncate or at most moderately 

 prolonged . . . . . . . . . . 



Anterior angles of head at least moderately prolonged; right 



! outer tubercle usually shorter, truncate or rounded, some- 

 times divided into two separate tubercles of which the outer 

 one or both may be more or less elongate and acute 

 (All six lamellae of antennae very long and slender; inqer 

 margin of right outer tubercle parallel to axis of body at base ; 

 anterior angles of head not prominent 



Proximal lamellae of antennae shorter ; inner margin of right 

 outer tubercle oblique throughout 



Apex of right outer tubercle truncate or imperfectly bifid in 

 profile, the suture distinctly bent downwards; anterior angles 

 of head not prominent ; mentum punctured sparsely or not at 

 all in middle (left upper tooth very variable) 

 Apex of right outer tubercle simply pointed in profile, suture 

 not bent downwards; anterior angles of head more or less dis- 

 tinctly prominent; mentum more or less strongly punctured 

 throughout . . . . . . . . . . 



Anterior angles of head not very prominent ; tip of right outer 

 tubercle as in /I. psrakensis, not bent outwards (fig. 33) 



321 

 1 the 



A. wallacei, pp. 228 & 5 



A. perakensis, pp. 229 & 287. 



\ Anterior angles of head more prominent; tip of right outer 

 I tubercle bent somewhat abruptly outv/ards 



A. möschleri, pp 229 & 287. 

 A. illegalis, pp. 230 & 287. 



