[1] The trilobites of this genus have slightly convex exoskeletons with an average length of 4–7 cm (1.5–3 in).

The glabella (center portion of the head) is often pear-shaped, and tapers outward toward the front.

The thorax is composed of eleven segments, with the relatively large pygidium with a slender axis of 11 to 16 rings and 6 or 7 pleural ribs.

Dalmanites is genus of trilobites with an average (about 8 centimetres or 3.1 inches long), moderately vaulted exoskeleton with an inverted egg-shaped outline (about 1.5× longer than wide).

The frontal margin of the cephalon is semicircular to parabolic, and it may have a simple and short anterior extension.

The "palate" (or hypostome), also only visible from the ventral side, is subtriangular (about as long as wide) and adorned with three weak denticles at its back rim.

[8] A specimen of an indeterminate species with preserved soft tissue is known from the Silurian aged Coalbrookdale Formation of England.