igi^.] F. H. Gravely : An Account of the Oriental Passalidae. 227 



ridges as usual, but is also continued outwards behind them as in specimens of 

 the sub-family Macrolininae— I know of no other species of Passalid in which this 

 occurs. The sides of the pronotiim are closely punctured below the scars throughout 

 their whole length ; the lateral plates of the ventral side of the prothorax are some- 

 what rougher and more punctured in front than in 0. birmanicus, which this species 

 resembles in all other respects. 



Ophrygonius inaequalis (Burmeister). 

 PI. xii, fig. 24-24^?. 



/■ 9120 9]2-l^ 9:UI-3 -J 



Regd. No. ] \j5i3"34o ' [Malacca Stoliczka bequest. 



' ~r 'w- ^ 



*^- Perak Moti Ram. 



~ 967|ii «s«. siukep Island Moti Ram. 



Description. — Length 24-27 mm- lyamellae of antennae (very short : only four of 

 them pubescent. Labrum hairy, but very sparsely punctured; sides slightly con- 

 vergent behind ; angles rounded, left one sometimes very much drawn out ; 

 anterior margin concave on both sides, convex in middle. Mandibles with upper 

 tooth obsolete on both sides; anterior lower tooth acutely conical (very sharp 

 when unworn), that of left side larger than that of right. Depression of anterior 

 margin of median part of mentum extensive, middle part of its posterior wall 

 bent forwards to form an angular prominence dividing depression into two more 

 or less completely separated halves. Head polished, but somewhat roughened 

 or punctured in front and at sides of (more rarely within) frontal area, and 

 sometimes about the middle-line behind central tubercle; parietal ridges directed 

 outwards, straight or somewhat S-shaped, usually defined in front by a groove; 

 keels of parietal and frontal ridges (latter sometimes coalescent behind) strongly 

 developed, continued to meet one another at apex of central tubercle; frontal 

 ridges so widely arched (even angular in some specimens) as to be parallel or 

 convergent in front ; inner tubercles indistinct, situated at base of inner side of 

 outer tubercles; margin of head between outer tubercles vertical, slightly (often 

 very indistinctly) convex in middle ; left outer tubercle very broad and more 

 or less inwardly directed at base, then abruptly narrowed from the outer side 

 and turned more forwards, bluntly rounded at the tip; ridge from left inner 

 tubercle straight and directed vertically forwards at the base, curving inwards distally 

 only where it has become faint; right outer tubercle somewhat long, pointed as seen 

 both from above and in profile, apex directed forwards and a little outwards; supra- 

 orbital ridges broadly rounded, not keeled behind, in front excavate, descending 

 abruptly at an angle of about 120° which is slightly peaked, the two walls of the 

 excavation keeled, outer one somewhat concave above forming with anterior angle 

 of head, an upwardly-directed tooth ; anterior angle of head containing somewhat 

 more than 120°, canthus vertically truncate at its extremity. Pronotum polished, 



