Page:The Eurypterida of New York Volume 1.pdf/360

 The swimming legs are small as in all Pterygoti; when turned back they do not reach the anterior margin of the fourth tergite.

The gnathobase is like that of ; and it probably possessed a like relation in size to the swimming leg and carapace.

In regard to the other joints of the swimming leg, we may also refer to the full description of these parts in the larger species from Buffalo, there being no specific differences apparent in these organs.

The metastoma is elongate cordate; its greatest width, which is a little beyond the middle, is about one half the length. The anterior margin is deeply emarginate, the posterior part contracted and the posterior end somewhat acutely rounded.

The endostoma has not been observed [see ].

The opercular appendages have not been preserved favorably in any of our specimens. The type of  [pl. 71, fig. 6] retains only the posterior portion of the operculum, together with the corresponding part of the opercular appendage, which indicates a short subtriangular organ that would correspond to the appendage of the male of other eurypterids. Near the broken edge the margin of an emarginate lobe is exposed and the posterior angle bears two dark spots suggestive of pores. The opercular appendage of the female has not been observed by us in this species.

The ornamentation agrees with that here described of.

Measurements. The few fairly complete specimens at our disposal are immature individuals. The specimen on plate 69, figure 2 gives the following measurements:

Length of carapace about 25 mm

Width, about 35 mm

Length of largest tergite, 11.5 mm

Width, 44.5 mm

Length of first postabdominal segment, 11 mm

Width, 39 mm