The oval, deeply domed adult carapace (to 28.1 cm) is broadest at the center, has a smooth posterior rim, but lacks a medial keel. A cervical scute is usually present, but neural bones are lacking. Vertebrals 1, 4, and 5 are broader than long, and the 5th is expanded posteriorly; vertebrals 2 and 3 may be as long as or longer than broad. Carapacial scutes are translucent and often rugose withraised longitudinal striations. The carapace ranges from olive brown to dark brown, with or without darker flecking. The plastron is long and narrow and the bridge is also narrow, leaving much of the carapacial opening uncovered. Its forelobe is rounded anteriorly and is broader than the hindlobe, which tapers to the rear and has an anal notch. The intergular is longer than broad and completely separates the gulars. Both plastron and bridge are cream to yellow. The head is moderate with a slightly upturned, projecting snout and an unnotched upper jaw. The mandibular symphysis is broader than the greatest diameter of the orbit. Chin barbels are absent or only poorly developed. Smooth skin covers the dorsal surface of the head; the neck has numerous low rounded scales. Head, neck, and limbs are dark gray. A yellow to greenish gray stripe extends backward from the orbit to the tympanum, and a second stripe of the same color passes backward along the lower jaw to the neck. Both jaws and the chin are light gray.

Diploid chromosomes total 50 (Bull and Legler, 1980). Females are larger and have higher domed shells and shorter tails than do the males.