6. Carapace having prominent ocelli, which are much larger near the center than at the sides _spinifer spinifer_, p. 489 Carapace having numerous small, dark spots, sometimes small ocelli, which are not much larger near the center than the sides _spinifer hartwegi_, p. 497 7. White spots on anterior third of carapace; white spots on carapace often surrounded by narrow blackish ocelli; small black dots sometimes interspersed among white spots _spinifer guadalupensis_, p. 517 White spots absent on anterior third of carapace, or small and inconspicuous; white spots not surrounded by narrow blackish ocelli 8 8. Pale rim of carapace narrow, partly obscured; over-all dorsal coloration (including soft parts of body) dark and lacking pattern; few, small, white tubercles confined to posterior third of carapace _ater_, p. 528 Pale rim distinct, without markings; soft parts of body dorsally not uniformly dark; many white tubercles usually contrasting on pale carapace 9 9. White spots confined to posterior third of carapace; ground color of carapace usually pale brown or tan, sometimes darker; a dark, slightly curved, line connecting anterior margins of orbits; postocular stripe usually interrupted leaving pale, blotch behind eye; pale rim of carapace four or five times wider posteriorly than laterally _spinifer emoryi_, p. 510 Small white spots on posterior half of carapace gradually decreasing in size anteriorly, often indistinct or absent on anterior third of carapace; pale rim of carapace no more than three times wider posteriorly than laterally _spinifer pallidus_, p. 522 10. Marginal ridge present; carapace having ill-defined dark blotches on uniform grayish, lacking whitish tubercles or well-defined black spots or ocelli; pale rim of carapace absent; tubercles on anterior edge of carapace resembling flattened hemispheres; anterior parts of plastron often visible in dorsal view; postocular stripe, if present, having thick, blackish borders _ferox_, p. 479 Marginal ridge absent 11 11. Carapace uniform pale brownish, lacking mottled and blotched pattern, white dots, black ocelli or spots 12 Carapace having mottled and blotched pattern, contrasting or not; white spots or tubercles, black ocelli or spots may be present 13