234 Illinois State Lahoratory of Natural History. 



specimen, though a finely developed one, is abnormal in the 

 possession of a pair of small symmetrical supernumerary mar- 

 ginals, one on each side of the nuchal plate, making thirteen 

 for each side and twenty-six in all. 



MALACOOLEMMYS, Grat. 



Gray, Cat. Tortoises, etc., in Coll. Brit. Mus., 1844, p. 28. 



Carapace depressed, keeled. Plastron moderately large, 

 immovably fixed to the carapace, with no transverse hinge, 

 emarginate before and behind. Wings of pectoral and 

 abdominal plates large. Axillary and inguinal plates present. 

 Alveolar surfaces of the jaws smooth. Digits 5-4, long, fully 

 webbed. 



A comma-shaped yellow mark behind each eye. Keels of 

 second and third dorsal plates concave before the tuber- 

 cles M. lesueuri. 



Spot behind eye not comma-shaped. Keels of second and third 

 dorsal plates uniformly convex before the tubercles. 



M. geographicus. 



Malacoclemmys lesueuri. Gray. Geographic Tortoise, 

 Map Turtle. 



Emya lesueurii, Gray, Syn. Rep., 1831, p. 12. 



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



256. 

 E?nys pseudo-geographica Holbrook, N. A. Herp., 1842, I., p. 



103, pi. 15.— DeKay, Nat. Hist. N. Y., I., Zool. III., Kept. 



and Amph., 1842, p. 19, pi. 2, fig. 8. 

 Qraptemys lesueurii, Agassiz, L., Contr. Nat. Hist. U. S., 1857, 



I., p. 436;IL, pi. 2, fig. 10-12. 

 Malacoclemmys pseudogeograpMcus, Davis and Rice, Bull. Ill 



State Lab. Nat. Hist., I., No. 5, 1883, p. 56; Bull. Chicago 



Acad. Sci., 1883. 



Carapace six to eight inches long. Depressed, with a ver- 

 tebral ridge, from which the sides slope like the roof of a house 

 in young, but are more convex in large examples. Keels of 

 second and third dorsal plates concave before the tubercles. 

 Plastron distinctly emarginate behind, angulate on each side 

 of the emargination. Very slightly emarginate in front^ 



