CRUSTACEA. 
105 
Facial Sutures normal, rapidly approximating on the broad frontal border 
Glabella broadly conate or sub-triangular, slightly constricted at the ante¬ 
rior angles of the eyes and rounded to the frontal extremity, wbicb is closely 
appressed upon the marginal sulcus. Width at the base equal to one-third 
that of the shield. Length greater than the width. Surface convex, de¬ 
pressed above, and sloping in all directions to the cheeks. Lateral furrows 
obscure, obsolete upon the test, but under favorable preservation sometimes 
visible upon the cast of the lower surface. A single example shows three 
pairs and the accessory furrows or pits, the anterior of these pairs being 
numerically the second, the first pair being obsolete. They are all inclined 
posteriorly, and the last or fourth pair reach almost to the occipital furrow. 
Occipital lobes conspicuous; occipital furrow narrow, scarcely widening on 
the cheeks; occipital ring moderately broad and flat, narrowing slightly upon 
the cheeks. 
Cheeks depressed on the summit about the orbital lobe, and sloping with a 
somewhat abrupt curve to the strong marginal sulcus. 
Eyes relatively large, and closely appressed to the glabella. Palpebral 
lobe very small; palpebral furrow shallow and elevated. 
Thokax sub-rectangular, lateral margins slowly approximating posteriorly. 
Length to width as 2 to 1. 
Axis broad and strongly arched, width upon the anterior margin more than 
one-third the width of the thorax. Sides evenly approximating to the 
pygidium. The segments are flattened, transverse, or with a slight forward 
curve toward the axial line. 
PleurcB flattened near the axis, and at about one-third their width deflected 
in a more or less abrupt curve to the margins. Pleural annulations grooved, 
the anterior limb of each becoming rapidly obsolete beyond the fulcrum. 
Pygidium. Posterior outline the arc of a circle whose center is the middle 
point of the body; when slightly compressed it is distinctly emarginate at 
the posterior extremity; border broad, moderately thickened. Length about 
one-half the width. 
