238 Illinois State Laboratory of Natural History. 



side nearly or quite in contact between the abdominals and 

 marginals. Head large, with gular barbels. Digits 5-4, fully 

 webbed. 



Plastron moderately wide. Wings of the abdominal plates 

 wide, with a deep groove behind. Head large, with arhom- 

 boidal plate above Cinosternum. 



Plastron narrower. Wings of abdominal plates narrow, not 

 grooved behind. Head of moderate size, with no plate 

 above Aromochelys. 



CiNOSTERNUM, SPIX. 



Spix [Kinosternon] Eanse et Testudinis brasiliensis species novse, 



1825, p. 17. 

 Wagler, Nat. Syst. Amph., 1830, p. 137. 



Carapace elongate, convex, smooth. Plastron moderately 

 large, rounded before, truncate or slightly emarginate behind. 

 Wings of abdominal plates wide, with a groove behind. In- 

 guinal and axillary plates with the wings of the abdominals 

 forming the bridge between plastron and carapace. Digits 5-4, 

 fully webbed. Head large, with a large rhomboidal plate above. 

 Tail with a terminal nail. 



Cinosternura pennsylvanicum, Gmel. Mud Tortoise. 



Tsstudo peimsylvanica, Gmel., Syst. Nat. 1788, 1., p. 1042. 

 Cistudo pennsylvanica, Say, Jour. Acad. Nat. Sci. Phila., 1825, 



IV., pp. 206, 216. 

 Testudo pennsylvanica, LeC, Ann. Lye. Nat. Hist. N.Y., 1829, 



III., p. 120. 

 Cinosternon pennsylvanicum, Dum. et. Bibr., Erp. G<5n., 1835, II., 



p. 367. 

 Kinosternon pennsylvanicu7n,'Ho\hT. N. A. Herp., 1842, 1., p. 127, 



pi. 21.— DeKay, Nat. Hist. N. Y., I., Zool. III., Kept, and 



Amph., 1842, p. 21, pi. II., fig. 4. — LeC, Proc. Acad. Nat. 



Sci. Phila., 1854, VII., p. 183. 

 Cinosternum pennsylvanicum, Davis and Rice, Bull. 111. State 



Lab. Nat. Hist. I., No. 5, 1883, p. 54; Bull. Chicago Acad. 



Sci., 1883. 



