Page:The Eurypterida of New York Volume 1.pdf/373

 species. The barbs are quite distinct in specimen, plate 77 figure 3 and still better shown in the fragment reproduced in plate 74, figure 5. They are broad and low near the point of the teeth and become sharp and narrow near its base. Between the larger teeth more numerous and much smaller denticles are everywhere intercalated. The movable ramus carries in its basal part two (in the younger) or three (in the older individuals) stronger teeth directed forward and an irregularly alternating series of mostly smaller teeth on the other parts. The latter all stand vertical in the jaw. One of them surpasses the others in length and is flanked by a group of teeth of about half its length. The edges of these are smooth. All teeth are longitudinally striated. The specimen, plate 77, figure 3, shows apertures near the base of the teeth on the movable ramus.

The walking legs or endognathites are not very well displayed in our material; and the basal segments fail in all save one specimen [pl. 57, fig. 3]. In the latter the coxae even retain the epicoxites in position, the only case observed in the entire eurypterid material at our disposal. The coxa is slender, with a sigmoidal curvature and the manducatory edge carries a series of about nine teeth. The first two segments appear to be short, ringlike. The legs are slender and relatively longer in this species than in most of its allies, attaining twice the length of the cephalothorax; smooth, cylindrical and tapering regularly toward the blunt spine forming the last joint. The middle segments were longer than both the basal ones and the last. The four pairs do not seem to have differed materially in length.

The swimming legs were relatively slender and small extending but little beyond the posterior margin of the third tergite in the older. The coxa is of enormous size in relation to the remainder of the leg. It is half as long as the latter, less the small paddle, and its expansion covers half the underside of the carapace [pl. 78, fig. 2]. Its principal part is rectangular in outline, the interior and posterior sides nearly straight and the others convex, the outer side having a deep sinus in the middle