Relatively delicate and elongate in comparison to other species. Widest across its ‘waist’. Both sides convex.
Capsule Size:
Approximately 53-78 mm long x 30-50 mm wide excluding horns (when soaked).
Horns (when present):
All four horns of similar length to one another; more than half the length of the capsule, but no longer than capsule length. One pair are flattened and often curl towards one another at the tips (giving the impression of a stag beetle). When the capsule is viewed side on, the other pair are curled upwards, in the style of a bobsleigh, with a strong downwards hook at the tips.
Lateral keels:
Absent.
Fields:
Absent or very shallow.
Characteristic features:
No lateral keels, and fields absent or shallow. Distinctive ‘bobsleigh’ curl to one pair of horns.