Ooperipatellus cryptus

The species O. cryptus is small, ranging from 9 mm to 18 mm in length. Each antenna features 30 rings. The jaw features two blades, an inner blade with five to seven accessory teeth, and an outer blade with no accessory teeth. This velvet worm features 14 pairs of legs, with the last pair fully developed and bearing claws. The dorsal surface of the body usually features 12 complete plicae (transverse ridges) per segment. Each foot features three distal papillae (one anterior, one median, and one posterior), but no basal papillae. On the fourth and fifth leg pairs, a nephridial tubercle divides the third spinous pad on each foot in the middle. In the male, crural papillae are present on leg pairs 6 through 13. The crural glands of leg pair 13 extend into the body cavity, but these glands are usually short and confined to the legs on leg pairs 6 through 11. The gonopore in the male is cruciform, with the cross dividing the genital pad completely only along the transverse axis. The gonopore in the female is a longitudinal slit on the ovipositor. The dorsal surface of this species is pale, ranging from beige to yellowish, with a blue or mauve stripe running down the middle of the back and blue or mauve papillae arranged in transverse rows. The legs are usually solid blue but can (rarely) feature orange spots. …

The species O. cryptus is found in or under rotting tree trunks. These velvet worms are usually hidden deep (8 cm to 20 cm) in heavily rotted logs rather than near the surface. This species is found in dense sclerophyll forests of Eucalyptus trees and in rainforests. When disturbed, this velvet worm quickly curls up into a tight coil as a defensive behavior. When coiled, the velvet worm rolls into crevices in the litter or soil. Given this behavior, this velvet worm is difficult to collect in the field.