The following pics show average adult vent shots and the basic features for sexing that species:
(Click on thumbnails to view larger image)
Females on the left, Males on the right
Cyrtodactylus sp. – Ring-tail
Male Below: note the cluster of spines at the front edge of the hemipenal bulge. Hemipenal bulges in these species can shrink in the non breeding season but the spine cluster can always be used for sexing
Pseudothecadactylus sp. – Giant Cave
Female Above: note that females in this species have slight hemipenal bulges and small hemipenal spurs. Males also undergo some hemipenal reduction in the non breeding season