20. TESTUDO. 153 
Nuchal minute ; lateral marginals formin 
an angle with the costals; beak feebly 
OOked Maer rp Mri ct aie aual ds eerie .» 13. trement, p. 163. 
b. A large subconical tubercle on the hinder side of the 
thigh. 
Nuchal minute; beak strongly hooked.... 14. tentoria, p. 164. 
Beak feebly hooked; suture between the 
gulars nearly as long as that between the 
COVSVUISUR Wis Sk tice, Ee Bd Gt oe RRs ee ORS 15. smithv, p. 165. 
Beak feebly hooked ; suture between the 
gulars much shorter than that between 
ERE FAMIAI SES Meyret a encjtenotics's =, od spsjeeris ie! ots yee yan 16. fiskii, p. 165. 
Beak strongly hooked; nuchal rather large, 
broadest posteriorly ; posterior margin of 
carapace strongly serrated............ 17. oculifera, p. 165, 
2. A pair of very large preefrontal 
shields; shell hemispherical; gular 
region of plastron more or less 
PLOdMCeM My ertucms cesta ates 18. radiata, p. 166. 
V. Long-necked, gigantic tortoises of uniform dark brown or black 
coloration. 
A. Nuchal shield present; gular shields distinct. 
1. Shields of carapace concentrically 
striated, and plastron notched 
behindainithe adult, 2 o¢.6.44 19. elephantina, p. 167. 
2. Shields of carapace smooth and plastron truncate behind in 
the adult. 
a. Width of plastral bridge two fifths the length of the 
carapace, which is declivous in front. 
Supracaudal shield divided ............ 20. gigantea, p. 168. 
Supracaudal shield undivided............ 21. hololissa, p. 168. 
b. Width of plastral bridge one third 
the length of the carapace, the 
anterior profile of which is 
MEATLYA NOTIZODUAIN wal serareh aes: 22, daudinit, p. 169. 
B. Nuchal absent ; gulars distinct. 
1. Shields of carapace concentrically striated in the adult. 
Plastron notched behind ; profile of carapace 
Aechivousainl LON eyepiece eet eee 23. nigrita, p. 169. 
Plastron truncate behind in the adult ; pro- 
file of carapace declivous in front ...... 24. nigra, p. 170. 
