112 
AUG. F. FOERSTE 
ible rings on the axial lobe which distinguish the pygidia here 
described under the name Calymene from those referred by 
Prof. Van Ingen to Cyphaspis arkansana. 
Proetus vaningeni Sp. nov. 
Plate XIV, figs. 3 A, B, C 
Five cranidia are at hand, of which the largest has a length of 
5.8 mm. The glabella is 4.7 mm. long, the anterior border of 
the cranidium is 1.1 mm. long, and the neck-ring is 1 mm. in 
length. The maximum width of the glabella at its posterior 
end is 3.9 mm. The glabella is strongly convex, both laterally 
and antero-posteriorly. In the latter direction its greatest 
convexity is about one-third of the length of the glabella from 
its anterior margin. Here the convexity of the glabella is full}^ 
1 mm. Along the posterior two-thirds of the glabella its antero- 
posterior curvature is distinctly less in an antero -posterior di- 
rection, though still fairly strong laterally. No trace of a pos- 
terior pair of lobes was detected, though the glabella widens 
slightly here. In general, the sides of the glabella are nearly 
parallel, converging slightly toward the front until the inward 
curvature of the facial sutures in front of the palpebral lobes is 
reached, but anterior to the latter the sides curve with increasing 
rapidity and the anterior margin of the glabella is evenly rounded. 
Along the anterior part of the glabella the antero-posterior curva- 
ture of the glabella is so strong that this part of the glabella 
tends to arch forward over the groove limiting its anterior mar- 
gin. No area intervenes between the anterior margin of the 
glabella and the median part of the anterior border of the cranid- 
ium for a width of a millimeter and a half. The upper surface 
of this border is flattish or gently convex, and inclines upward 
and forward at an angle of about 160° with the general horizontal 
plane of the cranidium. The neck furrow is deep. The neck- 
ring is unarmed with any median tubercle as far as known. The 
palpebral lobes are 0.75 mm. in width, and their anterior margin 
extends 2.4 mm. in front of the rear margin of the glabella. The 
surface of the cranidium is almost smooth, even under a lens. 
