274 NEW YORK STATE MUSEUM 
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 Williamsville, 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. 
Dolichopterus (?) testudineus' nov. 
Plate 57, figure 2 
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 
1In allusion to the turtlelike head. 
