236 Illinois State Laboratori/ of Natural History. 



Emys geogruphica [in part], Dum. et. Bibr., Erp. Gen., 1835, II. 



p. 256.— Holbr., N. A. Herp.. 1842, I., p. 99, pi. 14.— DeKay ' 



Nat. Hist. N. Y., I., Zool., ILL, Kept, and Amph., 1842, p. 18, 



pl. 4, fig. 7. 

 Graptemys geogra,phica, Agassiz, L., Contr. Nat. Hist. U. S., 1857, 



L, p.436; IT., pl. 2, fig. 7-9. 

 Malacoclemmya geograpMoufi, Davis and Rice, Bull. 111. State Lab. 



Nat. Hist., 1., No. 5, 1883, p. 56; Bull. Chicago Arad. Sci., 



1883. 



Carapace eight to ten inches long. Depressed, bluntly 

 keeled. Keels of the dorsal plates regularly convex, posterior 

 tubercles not very prominent. Sides a trifle less convex than 

 in M. lesueuri. Outer margins of posterior marginal plates 

 sinuate, and bluntly toothed. A wide notch between the two 

 caudals. Plastron distinctly emarginate behind, slightly or not 

 at all in front. Anterior angles of the gulars slightly pro- 

 duced, outer lateral margins of these plates sinuated. Axillary 

 and inguinal plates equal. Posterior margins of anal plates an- 

 gulate. Head very large, its width contained about 4.6 times 

 in length of carapace. Alveolar surfaces of jaws very wide, 

 the inner edges almost meeting at the middle line. 



Carapace above olive brown, obscurely reticulate with nar- 

 row yellow lines. An undefined black spot on the posterior end 

 of the vertebral keel of each dorsal plate. Black blotches 

 at sutures between costal and marginal plates, sometimes also 

 a pair of black dots on the dorsals. Marginal plates beneath 

 with reniform blotches, including one or more yellow lines. 

 Axillaries, iuguinals, and outer extremities of pectorals and 

 abdominals marked with similar lines of dark and yellow. 

 Plastron in adults largely yellow. Lines of union between 

 plates gray or black; in young often with dark spots with pale 

 centers in the anterior inner angles of abdominal plates. Head, 

 neck, legs, and tail striped. Characteristic marks are as fol- 

 lows: a longitudinally-placed spot behind each eye; a narrow 

 dorsal line extending from the snout backward to about opposite 

 the anterior margin of the spots behind the eyes, where it ter- 

 minates abruptly; a stripe originating on each tympanum and 

 thence extending downward and backward on the neck; and a 

 stripe on the symphysis of the mandible. 



