Reptiles and Amphibians of Illinois. 227 



and costals arranged in transverse series of threes, never alter- 

 nating as in C. marginata. Anterior lateral angles of the 

 gulars, with a blunt tooth. Margins of the first marginals, the 

 gulars, and the anals sometimes serrate. Pectorals transverse, 

 very narrow, scarcely half the size of the abdominals. Upper 

 jaw notched, with a sharp tooth on each side of the excision. 

 Anterior feet smallest, with five digits. Posterior feet ex- 

 panded distally, with four digits. 



Color above olive-brown, or dull black, with a narrow ver- 

 tebral line; median plates with yellow margins. Marginal 

 plates with parallel or concentric yellow lines; all the yellow 

 lines edged with black. Under side of marginal plates with 

 large marginal spots, or almost entirely, red or yellow. Plastron 

 yellow or orange, with an obsolete central dark area, the latter 

 sometimes made up of approximated gray and yellow stripes. 

 Neck, feet, and tail striped with red and yellow. 



Size and proportions nearly the same as in C. marginata. 



Mt. Carmel (Nat. Mus.). 



Under the name C. picta this and the closely allied C. 

 marginata are included by good authorities as varieties of one 

 species, and as the former name has the right of priority it has 

 come to be commonly applied by students to the individuals of 

 the genus taken in Illinois. It is very probable, however, that 

 C. picta will be found to be very rare in this State, if it occurs 

 at all. C. marginata is at any rate the common species. Pre- 

 vious to the publication of Kennicott's list of the animals of 

 Cook county the two species were not discriminated by natu- 

 ralists, and his statement as to the abundance of C. picta in 

 the State doubtless applies to the other species. The two 

 species may always be known by the difference in the relative 

 positions of the dorsal and costal plates. Otherwise the differ- 

 ences between them are not marked. In habits they are alike, 

 both frequenting lakes and ponds. They are occasionally 

 found in small streams, but their preference seems to be for 

 quiet water in which there are partly submerged rocks or logs 

 upon which they may climb to bask in the sun. They are 

 harmless and timid, slipping hurriedly into the water when 

 approached. They are said to eat both animal and vegetable 

 food. The eggs are elongate and are deposited by the mother 



