but less active and movable organ. The coxa has not been seen entirely free. Enough, however, is shown to indicate that it is of a rhomboidal outline, like that of Eurypterus, differing in that it is relatively higher and shorter [pl. 32]. The gnathobase is not preserved in the specimen cited. The second segment is not short and ringlike as in Eurypterus, but cup-shaped, widening rapidly distally. It is connected by the narrow ringlike or wedge-shaped third segment to the ringlike fourth segment. In an old
 Figure 57 Eusarcus scorpionis Grote & Pitt. Portion of dorsal view of left swimming leg. Natural size. Original in State Museum |
individual [text fig. 57] the three segments mentioned form a powerful spherical part of the leg. The fifth segment is ringlike on the underside of the limb, widens out and is extended anteriorly on the upper side. Near the center of the flaring upper portion of this segment the next, sixth, segment is inserted. This appears from both sides as a triangular, or originally rather conical body, the distal basal surface of which is deeply emarginate on the posterior side and extended on the anterior, so as to fit into the deeply emarginate basal portion of the seventh joint. The latter is by far the broadest segment of the limb and nearly as long as
