LEPTAULAX. 247 



long lamellae only. Head symmetrical, the front margin 

 bearing four straight, narrow teeth. Pronotum with strong 

 complete median groove and sharp or rather shaq) front 

 angles. El\-tra long and wings fully developed. Metasternum 

 with the ])rimary lateral de])ression very narrow, and a secon- 

 dary and much broader lateral depresst^l area very shar|)ly 

 defined on each side of the smooth median area. Mandible 

 with a shai-jj tooth at the outer etlge. Maxilla with the outer 

 lobe not very slender and the inner lol)e short and simple. 

 Mentum rather short, the basal part relatively long with very 

 deep lateral scars ; the ligula short and bluntly pointed at the 

 extremity ; the labial palpi with the terminal joint well 

 developed and the i)receding joint not much dilated. 



The species of this genus, all of Avhich are rather flat, are 

 found, together with their larvse and i)up;o, just beneath the 

 bark of decaying logs. They seem to ])cnctrate less deeply 

 than other Passalid^ into the substance of the wood. 



Key to the Species. 



1 (4) Sides of the elytra with sealari- 



form piinctiiratioii. 



2 (3) Metasternum without irregular 



puncturation on the median 



area dentatun F., j). 247. 



3 (-) Metasterniim irregularly punc- 



tiu-ed on tlie median area . . . cydotunius Kuw., p. 248. 



4 ( 1 ) Lateral grooves of the elytra sim- 



ply punctured. 



5 (8) Abdomen not entirely punrtured. 



6 (7) Marginal gi'ooves of the pronotiun 



eoarse bicolor F., p. 249. 



7 (6) Marginal grooves of the pronotum 



fine rcepstorjji KuSv., p. 249. 



■8 (5 Abdomen entirely and coarsely 



punctured planus 111., p. 250. 



143. Leptaulax dentatus. (Plate XXIII, fig. 8.) 



Pasmliis dentatus F., Ent. Syst. i, 2, 1792, p. 241. 

 Leptaulax dentatus Gravely, Mem. Ind. Mus. iii, 1914, p. 252, pi. 13, 

 fig. 52 ; op. cit. vii, 1918, p. 116. 



Very shining, rather flat. The head bears large scattered 

 annular punctures, the front margin bears four equal and 

 nearly ecjuidistant teeth in a straight line and a smaller one in 

 the middle, the median area is narrow and bisecte<l bj' a strong 

 ridge, the supraorbital ridge is strongly elevated but scarcely 

 toothed and not comiected with the parietal ridge. The 

 pronotum is strongl}^ transverse, its front angles are rather 

 blunt, the hind angles narrowly rouiided, the sides closely and 

 rugosely punctured behind antl more sparmgly in front. The 

 dorsal striae of the elytra are very minutely punctured, the 

 intervals flat and the sculpture of the sides is scalariform. 



