936 



FAMILY L. — SCARAB^IDJE. 



Tribe IV. GEOTRUPINI. 



Rounded, convex beetles having the mandibles and labrum 

 prominent, of horn-like texture ; antennas 11-jointed, club 3-jointed, 

 variable in form ; elytra usually strongly striate, covering the abdo- 

 men ; the middle coxa?, ventral segments and tarsal claws as in Tribe 

 III. The thorax of some males, and more rarely the head, is armed 

 with horns or tubercles. Most of the species live in excrement; 

 others, according to Horn, are veritable hoboes, "wandering about 

 without visible means of support," The principal literature treat- 

 ing of the North American members of the tribe is as follows : 



Horn. — "Notes on Genera of Coprophagus Scarabasidas of the 

 U. S.," in Trans. Amer. Ent. Soc, III, 1870. The genera 

 Bradycinetus, Bolboceras and Odontceus are treated on pp. 

 48-50. 



Horn. — "Geotrupes of Boreal America," in Trans. Amer. Ent. 



Soc, I, 1868, 313-322. 

 Horn. — "Synopsis of the G-eotrupes of the U. S.," in Trans. 



Amer. Ent. Soc, VIII, 1880, 145. 

 Blanchard, Frederic 1 ,:. — "Some account of our Species of Geo- 



trupes," in Psyche, V, 1888, 103-110. 

 Sehceffer, Chas'.— "On Bradycinetus and Bolboceras of North 



America, with Notes on other Genera," in Trans. Amer. Ent. 



Soc, XXXII, 1906, 249-278. 

 Of the five genera of Geotrupini recognized from the United 

 States, representatives of four have been taken in Indiana: 



KEY TO INDIANA GENERA OF GEOTRUPINI. 



a. Club of antennae large, round, convex on both sides. (Fig. 4, No. 14.) 

 &. Eyes only partially divided by a process from the side of bead. 



XII. Bolboceras. 



1)1). Eyes entirely divided. 



c. Color above black and reddish-brown ; process between the middle 

 coxae with an erect tooth-like elevation. 



XIII. BOLBOCEROSOMA. 



cc. Color above uniform chestnut brown ; process between the middle 

 coxae without a tooth-like elevation. XIV. Odont.eus. 



aa. Club of antennae smaller, composed of leaf-like plates. XV. Geotrupes. 



XII. Bolboceras Kirby. 1818. (Gr., "bull + horn. ") 



This genus is principally distinguished by having the eyes only 

 partly divided and by the middle coxa? being continguous or very 

 close together. 



