is associated at New Campbellton with abundant Anthracomya in a series of strata which present strong evidence of freshwater deposition.
SUBCLASS MEROSTOMATA
Genus Schistaspis
Schistaspis (σχιστός cloven; ἀσπίς shield)—Cephalic shield relatively large, hemispherical, smooth, with no distinct prominences or glabellar region. Paired median simple eyes doubtfully present near the anterior margin. Head shield articulated behind with a post-cephalic shield whose wing-like expansions are directed outwards and backwards. Abdominal free segments 8 (?) in number, non-trilobate, with spine-like posteriorly directed epimeral projections. The first seven abdominal segments are single. The last abdominal segment is anchylosed to a small hemispherical tail plate which doubtfully bore a telson spine in articulation with it.
Schistaspis bretonenis n. sp.
Description: Length, exclusive of possible telson spine, 27 mm.; maximum width 12.6 mm. Cephalic shield large, with hemispherical outer border, and concave, evenly curved posterior border. Genal angles acute but scarcely prolonged into a spine. Lateral margin with a narrow raised border which disappears, or is folded beneath, at the extreme front. Although the shield is crushed and somewhat fractured, there is no evidence of a raised glabellar region, nor could the definite presence of compound eyes be detected on the dorsal surface. Medially, however, and situated 1.1 mm. from the front margin there is a minute circular mound about 1/5 mm. in diameter which doubtfully may represent one of a pair of simple eyes. It lies a little to the left of the median line and the corresponding position to the right is obscured by a bit of matrix.
Behind the cephalic buckler and free from it, there is a crescentic shield whose anterior convex margin follows the contour of the shield in front. The lateral angles are acute but blunter than the cephalic genal angles. They lie about opposite the fourth abdominal segment. The posterior margin of this thoracic shield is triangular, the two straight edges enclosing in one specimen an angle of 116°, in the other an angle of 103°.
The first two visible abdominal segments are partly covered by overlap of the crescentic shield. The succeeding five segments are simple and free, with straight axial border in the frontal region of the abdomen but becoming arched in the posterior region. The epi-
