128 C0LE0PTERA OF NORTH AMERICA. 



alone represents this tribe in our fauna. It is an oval, convex, 

 shining black insect, about a quarter of an inch long, with fine 

 rows of punctures on the elytra. 



The mandibles and labrum are corneous, prominent; antennae 

 10-jointed, the club 3-jointed, the first joint hollowed and receiv- 

 ing the second ; anterior coxae conical, prominent ; middle coxa? 

 oblique, contiguous; epimera of the metathorax visible; ventral 

 segments six, all but the last connate. Tarsi with a short bise- 

 tose onychium. 



Tribe V.— GEQTRITPINI. 



Insects of rounded convex form, some living in excrements, 

 others found wandering about without visible means of support; 

 . the elytra strongly striate in nearly all ; the thorax of the males, 

 and more rarely the head, armed with horns or tubercles. 



The mandibles and labrum corneous, prominent; antennae 11- 

 jointed, club 3-jointed, variable in form; anterior coxas promi- 

 nent; middle coxa? more or less oblique, usually contiguous, but 

 separated in Athyreus ; epimera of the metathorax visible ; ventral 

 segments six, free; the elytra covering the pygidium; tarsi with 

 a bisetose onychium. 



With the exception of one species of Odontaeus from California, 

 our species are all found east of the Rocky Mountains. 



Club of antennae large, lenticular ; 



Middle coxse separated. Athyreus. 

 Middle coxa? contiguous ; 



Eyes partially divided. Bolbocekus. 



Eyes entirely divided. OdontjEus. 



Club of antennae lamellate. Geotkupes. 



Tribe VI.J-PUEOCOMIIW. 



This tribe contains but a single Californian species, Pleocoma 

 fimbriata Lee, of moderately large size, black, rounded, not very 

 convex, with the body, parts of the mouth, and legs clothed with 

 very long hair. The elytra are irregularly punctured, and the 

 head is armed with a perpendicular horn between the eyes, and 

 the front is prolonged and bifurcated ; above the insertion of the 

 antennae is an acute lobe. The antennas have eleven joints, of 

 which the last five or six form a large lamellated mass ; the labrum 

 is elongated, rounded at the apex, and deflexed. The mandibles 



