1918.] 



F. H. Gravely : Passalidae of the World. 



83 



9 



10 



The six antennal lamellae stout and as a rule not very long, 

 the first three usually, yery short; species from the Indian 

 Empire, Indo-China, (?) Siam and Ceylon 

 The six antennal lamellae long and slender ; species from the 



Malay Peninsula, Sunda Islands, Philippines and Celebes 

 The ridge joining the inner tubercles separated from the anterior 

 margin of the head throughout its whole length by a more or 

 less concave surface ; species from the Indian Empire, 

 Indo-China and (?) Siam . . 

 The ridge joining the inner tubercles closely approximated 

 to the anterior margin of the head either in the middle or 

 throughout ; species from Ceylon 

 The lateral grooves of the elytra narrow, their punctures 



normal 

 The lateral grooves of- the elytra broad, their punctures 



transversely linear 

 The outer tubercles slender in profile, truncate ; the ridge 



joining the inner tubercles concave 

 The outer tubercles stouter and distinctly bifid in profile, the 

 ridge joining the inner tubercles straight 

 r The ridge between the inner tubercles straight throughout 

 almost its whole length ; the anterior angles of the pronotum 

 unpunctured ; the antennal lamellae somewhat long 

 The ridge between the inner tubercles convex, evenly curved 

 throughout ; the anterior angles of the pronotum strongly 

 punctured ; the antennal lamellae short 

 The lateral grooves of the elytra almost as broad as the 



intervening ridges, their punctures very coarse indeed 

 The lateral grooves of the elytra much narrower than the 

 intervening ridges 

 r The elytra separate, parallel-sided, with finely punctured 



grooves 

 I The elytra united, more ovate, with coarsely punctured grooves 

 / The frontal area small and unpunctured ; the inner tubercles 

 large and connected by a strongly concave ridge ; the marginal 

 grooves of the pronotum hairless in the anterior angles 

 The frontal area large and punctured all over ; the inner 

 tubercles small, and connected by a ridge which is straight as 

 a whole and situated immediately above the anterior margin 

 of the head, and may have a more or less angular median 

 convexity ; the marginal grooves of the pronotum hairless 

 only in their anterior terminal enlargements 

 ( The anterior angles of the pronotum strongly and extensively 

 punctured ; the pronotal scars with a few small hairs 

 The anterior angles of the pronotum with not more than one 

 or two punctures ; the pronotal scars thickly hairy 



8 



3. 



9. 



6. 



5. 



M. sikkimensis, p. 80. 

 M. nicobaricus, Gravely. 

 M. andamanensis, p. 80. 



M. waterhousei, Kaup. 



7. 



M. crenatipennis, Kuwert. 



M. rotundifrons, p. 80. 

 M. obesus, p. 80. 



10. 



11. 



M. batesi, p. 81. 

 M. depressus, p. 81. 



m 2 



