8. MALACOCLEMMYS. 89 
Synopsis of the Species. 
Carapace much depressed ; the length of 
the hind lobe of the plastron much ex- 
ceeds the width of the bridge ........ 1. terrapen, p. 89. 
Carapace tectiform, the vertebral keel obtuse 
and not tubercular; hind margin but 
moderavely, SeLrabeds ©. mers sos) esis 2. geographica, p. 90. 
Carapace tectiform, with strong vertebral 
keel ending in a tubercle on each shield ; 
posterior margin very strongly serrated . 3. lesuewri, p. 91. 
1. Malacoclemmys terrapen. 
Testudo terrapin, Schoepff, Test. p. 64, pl. xv. (1792). 
centrata, Daud. Rept. i. p. 155 (1802). 
concentrica, Shaw, Zool. iii. p. 43, pl. ix. (1802). 
Emys centrata, Schweigg. Prodr. p. 32 (1814); Say, Journ, Ac, 
Philad. iv. p. 205 (1825). 
ae palustris (non Gmel.), Leconte, Ann. Lye. N. Y. iii. p. 115 
(1830). 
Terrapene palustris, Bonap. Osserv. s. sec. Ed. d. R. A, p. 157 (1830). 
Emys concentrica, Gray, Syn. Rept. p. 27 (1831); Bell, Mon. Test. 
pl. — (1854); Dum. § Bibr. i. p. 261 (1835). 
terrapin, Holbr. N. Am. Herp. i. p. 87, pl. xii. (1842); Dekay, 
Faun. N. Y., Rept. p. 11, pl. xxiii. fig. 63 (1842); Wied, N. Acta 
Ac, Leop.-Carol. xxxii. 1. p. 16 (1865). 
palustris, Dekay, 1. ce. p. 10, pl. iii. fig. 5. 
Malaciemys concentrica, Gray, Cat. Tort. p. 28 (1844), and Sh. Rept. 
i. p. 37 (vars. concentrica, centrata, tuberculifera) (1855), and 
Suppl. p. 42 (1870). 
Emys macrocephala, Gray, Cat. Tort. p. 26. 
Malacoclemmys palustris, Agassiz, Contr. N. H, U.S. i. p. 487, pl. 1. 
figs. 10-12 (1857). 
Clemmys terrapin, Strauch, Chelon. Stud. p. 182 (1862), and Verth. 
Schidkr. p. 90 (1865). 
Emys pileata, Weed, J. c. p. 17, pl. i. figs. 2 & 3, & pl. il. figs. 1-4, 
Carapace much depressed, oval, posterior border sometimes dis- 
tinctly reverted, very rarely serrated ; a more or less strong, inter- 
rupted, vertebral keel or series of subconical tubercles; dorsal 
shields concentrically grooved, or smooth; nuchal moderate, as 
broad as long or a little broader than long; first vertebral broader 
anteriorly than posteriorly ; vertebrals 2 to 4 much broader than 
long, broader than costals. Plastron a little smaller than the 
opening of the shell, obtusely angulated laterally ; bridge rather 
narrow, its width considerably less than the length of the hind 
plastral lobe ; latter openly notched posteriorly ; relative proportions 
of the plastral shields very variable ; the suture between the abdo- 
minals and that between the anals are of equal length, or the latter 
is the shorter; pectorals usually much smaller than abdominals, 
sometimes very slightly smaller; axillary and inguinal rather small. 
Head large; snout short, more or less obtusely pointed ; upper beak 
