doublure, the inside face of the boards, especially applied to them when lined with leather and decorated.
It is also known that the epistoma is narrower and more firmly fused into the doublure in later than in earlier species.
Since the front of the hypostoma is attached to this doublure, it stands high up within the vault and under the glabella.
Width of doublure of front of cephalon on median line, 17 mm.; length of hypostoma, 20 mm.
They occur near the anterior margin of the segment, and near the inner end of the doublure.