1918.] 



F. H. Gravely : Passalidae of the World. 



65 



P. nanus, p. 52. 

 P. rugosus, p. 52. 



J 



This species differs from the last only in the form of the frontal area, which is slightly 

 longer in proportion to its width and is more or less distinctly grooved in continuation of 

 the median notch on the anterior margin. 



The species of Passalus known to me may be distinguished from one another thus : — 



/The punctures in the grooves of the elytra extremely coarse, 

 transverse laterally ; the anterior margin of the head straight 

 between the outer tubercles ; the lateral areas of the metas- 

 ternum hairless (small insects only) . . . . . . mm 2. 



1 n The punctures in the grooves of the elytra less coarse, not 

 transverse laterally ; or, the anterior margin of the head 

 strongly notched in the middle ; or, the lateral areas of the 

 metasternum hairy . . . . . . . . . . . . 3_ 



The epipleura hairless 

 The epipleura hairy 



/The anterior margin of the head straight or simply notched 

 in the middle, without secondary tubercles ; the frontal 

 area large, with the central tubercle about half as far from 

 the anterior margin as the outer tubercles are from each 

 other, and with the frontal ridges usually straight and 

 diverging at about a right angle ; the central tubercle small, 

 without free apex ; the outer tubercles prominent, the inner 

 tubercles usually situated very near them, always nearer 

 to them than to the central tubercle ; the lateral areas of 

 the metasternum, and the epipleura and shoulders of the 

 elytra, hairless 

 Not as above . . . . . . . . . . . . . , 4_ 



/The anterior margin of the head straight between the outer 

 tubercles ; the clypeus entirely hidden ; the central tubercle 

 smal! with no trace of free apex ; the inner tubercles usually 

 much less widely separated than the outer, and when 

 distinct always situated a considerable distance behind them ; 

 the frontal ridges straight, not arched, meeting in a distinct 

 though sometimes more or less obtuse angle ; the epipleura 

 usually hairless, when hairy the lateral areas of the 

 metasternum always hairy also . . . . . . . . . . 5. 



Not as above . . . . . . . . . . . . . . 9_ 



f The inner and outer tubercles equally widely separated, the 

 ] fomer situated at a considerable distance behind the latter ; 

 J the epipleura densely hairy . . . . . . P. rhodocanthopoides, p. 53 . 



( Not as above . . . . . . . . . . . . . . 6_ 



r The anterior margin of the head usually somewhat thickened ; 

 the outer tubercles obsolete, obtuse ; the frontal ridges 

 ending in the inner tubercles, which are very pronounced 

 and are situated about half way between the central and 

 outer tubercles . . . . . . . . P. morio, p. 54. 



Not as above . . . . . . . . . . . . 7_ 



P. punctato-slrialus, p. 52. 



' 



I 



6^ 



K 



