Page:Cincinnati Quart. J. Sci. 2 347-349.djvu/2

348 Movable cheeks; upper margin forms the base of the eye; anteriorly an acute angle terminating under the anterior base of the eye; posterior margin with two spines; the inner short, sharp pointed, curves downward and backward on a line with the pleura of the first segment of the thorax; outer spine long, nearly flat, obliquely striated, terminates opposite the axial lobe of the fifth segment.

At the anterior base of the eyes the outer margin of the movable checks curve abruptly downward and under forming a doublure, which extends around under the anterior margin of the glabella, and backward under the cheeks to a line with the neck segment.

Eyes large, elongated, depressed, occupy the curved space between the upper margins of the cheeks and the lateral margins of the glubella: perpendicular in hight to each, surface finely reticulated.

Facial sutures cutting the neck segment on a line with the base of the eyes, extend obliquely up to the posterior lateral angles of the glabella; curve outward around the top of the eyes, then abruptly down forming their anterior margin, curving forward and slightly upward they unite in front of the glabella.

Hypostoma; body quadrate, buccal margin produced into two long tapering lobes, with a deep buccal notch between them; upon the ventral surface four elevated lines run the length of each lobe, two central and one on each margin, the marginal lines of the outer margins continue to the anterior margin of the body, three short lines separating them near the anterior margin; muscular scars slightly elevated, oval, situated anterior to the buccal notch, they are crossed by minute inosculating lines. Interior or dorsal surface of the body cut away anteriorly forming a semi-circular depression, showing the interior of the ventral surface, and muscular scars as slight depressions crossed by minute striæ; ventral surface minutely tubercular, interior surface smooth. The hypostoma was attached to the doublure beneath the glabella; the extremities of the buccal lobes extending back to the anterior edge of the seventh thoracic segment.

Thorax with ten segments arching forward, narrows rapidly to the pygidium; axial lobe separated from the plural lobes, by a sharp ridge extending two-thirds the distance across each segment, a slight diagonal furrow crosses the segments of the axial lobe near the junction of the axial and plural lobes. Pluræ flat, curving down one-half the way outward where they are reflected backward, terminating in short pointed extremities.

Pygidium small, subquadrate, posterior margin narrowing is divided