Page:The Eurypterida of New York Volume 1.pdf/280

 fourth the length of the carapace, are broadly oval in shape and only 4 mm distant from the margin, at the antelateral angles. The ocelli have not been seen. An obscure tumescence which may have borne them is noticeable midway between the posterior portions of the lateral eyes. The doublure of the carapace does not seem to have been very broad on either the front or the sides. The surface is smooth.

Measurements. The carapace measures 81 mm in length along the median line and 85 mm where it is longest. It is 77 mm just in front of the eyes, 108.5 mm in its widest part and about 99 mm at the base.

Horizon and locality. Rare in the Bertie limestone at Williams ville, N.Y.

Observations. There is no other species in our faunas, save a small form from Otisville, with both similar outline of carapace and like anterior position of the eyes. Nor are we aware of European forms that invite comparison.

Description. A single uncompressed carapace from the Bertie beds is of small size, obovate in outline; the greatest width, which surpasses the length by one tenth, forward of the middle, just behind the eyes; thence the well rounded margins converge to a point in front; and they also converge rather strongly toward the base of the head shield, so that the latter is but three fourths as wide as the widest part of the carapace. As the lateral and frontal margins form an evenly rounded curve, no indications of antelateral angles are present, but a slightly projecting anteromedian or frontal angle is produced. The posterior margin is broadly concave in the middle and gently curved forward at the genal angles, so that the latter are obtuse and rounded.

By breaking away parts of the head shield a broad doublure is exposed. It passes all around to the genal angles, where it is abruptly cut off; the posterior margin being lined by a very narrow doublure. The