200 THE CANADIAN ENTOMOLOGIST. 



ee. Smaller species, .14 to .34 in. Onychium 



present Oiithophagus. 



cc. Hind tibiae with two spurs. Species oblong-convex or 

 subcylindrical, usually small. 



f. Mandibles visible beyond the clypeus ^gialia. 



ff. Mandibles not visible beyond the clypeus. 



g. First five strise of elytra reaching apical margin (in 



the Canadian species) , Pleurophorus. 



gg. First five striae not reaching apical margin. Head 

 punctured or slightly plicate. 

 h. Outer apical angle of hind tibiae prolonged, 



spiniform Atcenms. 



hh. Outer apical angle of hind tibiae obtuse. 



Front tibiae strongly toothed on outer 



margin Aphodhis. 



Front tibiae with outer teeth obtuse except at 



tip Dialytes. 



bb. Antennae ii-jointed, mandibles prominent, visible from above ; 

 form often very convex, rounded, 

 i. Club of antennse very large, lenticular. Brown or spotted 

 species. 



Eyes partially divided by sides of head. Males with 



short flattened horn Bolboceras. 



Eyes entirely divided. Males with long slender 



horn Odontceus. 



ii. Club of antennse looser, more flattened. Black bluish or 



greenish species Geotriipes. 



AA. Abdomen with five visible ventral segments. 



Tarsi with distinct bisetose onychium. Thorax strongly 

 narrowed before and behind, angulate at middle. Sculpture 



not very rough Nicagtis. 



Tarsi with distinct claws, no onychium. Thorax less narrowed 

 anteriorly, not angulate at middle. Sculpture very rough Trox. 



Canthon, Hoffm. 



The Canadian species are black or slightly bronzed insects which may 



be seen rolling balls of excrement from place to place. These balls are 



buried and the eggs deposited therein, thus ensuring the larvae a supply 



of food. They may easily be distinguished from the three following 



