• Body sleder, tapering at both ends.

• Cuticle thick, finely striated transversally, Lateral fields prominent or bearing lateral body alae that extend from cervical region and terminate anterior to tail.

• Cephalic region rounded or subquadrangular, without lateral alae.

• Oral opening  spindle-shaped slit, surrounded internally by collarette with approximately 100 raised small denticular thickenings.

• Cephalic region with circumoral group of 2 pairs of large papillae, 2 pairs of internal papillae, and 1 pair of large amphids

•  Esophagus entirely muscular, expanded in width at both ends. Anterior dilation slightly larger than or similar in size to posterior expansion. Esophastome (pseudobuccal capsule) well developed. Peribuccal rim with keyhole form, heavily sclerotized, with no pseudobuccal teeth. Buccal frame well sclerotized, with dorsal arrow-shaped structures extending laterally; large lateral structures posterior to peribuccal rim, lateral reniform structures, and transverse ventral plate.

• Nonsclerotized, esophago-intestinal valve extending into lumen of anterior intestine.

• Intestine without cecum. Intestine dilated at initial portion.

• Anus situated on small protuberance. Excretory pore beyond posterior end of esophagus

• Tail long, conoid with long, fine, hooklike sclerotized tip.

Female:

• Didelphic, amphidelphic;

• Ovaries reflexed

• Vulva at 60-63% of body length.

Male:

• Monorchic, testis reflexed

• Spicules slightly unequal length

• Gubernaculum weakly clerotized

• Caudal papillae, 10 pairs, (3 precloacal, 4 adcloacal, 3 postcloacal.

• no caudal alae

Ref:  Mejia-Madrid and Aguirre-Macedo, 2011.