1963] 
Matthews — Behavior of Canthon 
77 
and the Southwest by the closely related C. imitator Brown, which 
also occurs in Oklahoma, Arkansas, Louisiana, and Florida. In 
northern Florida east of the Apalachicola River and in southern 
Georgia a green or bronze phase of pilularius largely replaces the 
usual black one, while in most of peninsular Florida the species is 
largely represented by a blue-black phase which becomes intensely blue 
in the Keys. A more extensive discussion of the color phases will be 
found in Halffter (1961). The present observations are on all three 
color phases — green or bronze, black, and blue-black — and several 
instances of sexual pairing between all possible color combinations 
were observed, supporting the taxonomic evidence that there are no 
specific differences between them. 
Morphology 
The beetles are large (10 — 19 mm in length), broadly oval, and 
somewhat flattened (figs. 1 — 5). The head and legs are used exten- 
sively in the behavior described below and should therefore be briefly 
described. The head is strongly flattened and broad, with sharp edges, 
and is an excellent digging tool. The fore tibiae are strongly flattened 
and provided with teeth on the outer edges. The forelegs are used 
extensively in cutting and manipulating the dung and in patting the 
surface of the dung ball, as well as in digging. The middle and 
hind tibiae are very slender and a little curved and are used in rolling 
and guiding the dung ball. For a very detailed study of the mor- 
phology of the genus, see Halffter (1961). 
The mouthparts have been described by several authors (Harden- 
berg, 1907; Mohr, 1930; Pereira and Martinez, 1956; Miller, 1961) 
and do not concern us here, particularly. The latter author showed 
that the molar surfaces of the mandibles are so constructed as to be 
capable of a very thorough grinding action. Beetles with a mandible 
removed were unable to feed. 
There is no sexual dimorphism, other than in the forespur, and it 
is therefore not possible to determine the sex of a beetle without 
examining it closely. This complicates observation somewhat and 
means that a behavior sequence must be interrupted or allowed to 
be completed before the sex of the participants can be determined. 
This can be done by looking at the forespur (a lens is usually not 
necessary) , which is bifurcate in the male and simply acute in the 
female. 
Ecology 
The autecology of this species has not been properly investigated 
(nor has that of any other American coprophage). It is common 
