THE LAMELLICOEN BEETLES. 



911 



KEY TO SUBFAMILIES OF SCARAB7EID/E. 



a. Abdominal spiracles situated in a line on the membrane connecting the 

 dorsal and ventral horn-like plates, the last one, like the others, 

 covered by the elytra ; upper surface of head usually much dilated 

 on the front and sides; dung eating or skin beetles. 



Subfamily I. Laparosticti, p. 911. 

 da. Abdominal spiracles, except the front one or two, not situated on the 

 membrane above mentioned, the last one usually visible behind the 

 elytra; upper surface of head rarely dilated; vegetable feeding spe- 

 cies. 



b. Abdominal spiracles in part situated on the superior portion of the 

 ventral segments, the rows of spiracles feebly diverging. 



Subfamily II. Melolonthin^e, p. 947. 

 bl). Abdominal spiracles (excepting the three front ones) situated on the 

 dorsal portion of the ventral segments, forming two rows which 

 diverge strongly. Subfamily III. Pleurosticti, p. 980. 



Subfamily I. LAPAROSTICTI. 



In addition to the characters above given the Laparosticti, or 

 Coprophaga, as they are sometimes called, are distinguished by hav- 

 ing the suture separating the clypeus from the head distinct, and 

 not transverse but extending upward toward the vertex; club of 

 antennas consisting of only three joints. They all live on decompos- 

 ing matter, most of them in dung or fungi. The subfamily is di- 

 vided into eight tribes, six of which are represented in Indiana. 



KEY TO INDIANA TRIBES OF LAPAROSTICTI. 



a. Abdomen with six visible ventral segments. 



b. Antenna? with eight to ten joints ; mandibles concealed by the cly- 

 peus except in the genera Aigialia and Oclwdceus. 

 c. Hind tibiae with a single terminal spur (except in Canthon nigri- 

 eornis) ; form shorter, rounded; end of the abdomen exposed. 



Tribe I. Coprini, p. 912. 

 cc. Hind tibiae with two spurs ; abdomen wholly covered by elytra ; 

 size usually small. 

 (1. Antennae 9-jointed ; form oblong-convex or subcylindrical. 



Tribe II. Apiiodiini, p. 920. 

 dd. Antennae 10-;jointed ; form oval, convex. 



Tribe III. Orphnini, p. 935. 

 bb. Antennae 11-jointed ; mandibles prominent, visible from above. 



Tribe IV. Geotrupini, p. 936. 

 aa. Abdomen with five visible ventral segments. 



e. Body partially contractile, rounded, smooth, shining ; scutellum rela- 

 tively large. Tribe V. Acanthocerini, p. 940. 

 ee. Body not contractile, oblong, convex, roughly sculptured ; scutellum 

 small. Tribe VI. Trogini, p. 941. 

 [58—23402] 



