Page:The Eurypterida of New York Volume 1.pdf/256

 fragment of a flat-topped carina such as is found in the other eurypterids, suggesting that the section of the telson does not differ materially from that in other genera. No traces of marginal serrae are observable in our specimens.

Appendages. What appear to be the tips of the chelicerae or preoral appendages are seen in the largest specimen, the chelicerae having there remained in normal position. If this view is correct, these appendages were relatively large and strong.

The ectognathites or walking legs are here developed into stout and long organs which, except for the first pair, protrude far beyond the carapace and by their width give the impression of great strength and importance. This impression is still more emphasized by the great length of their curved spines. The first leg was the shortest, only its last two segments and their spines protruding. The second walking leg which is the longest, is exposed with six segments outside of the carapace; its exposed portion equals the carapace in length. The segments in this pair of appendages are about as long as wide; in the following legs they become increasingly shorter. The spines attain about one fourth the length of the ectognathites, the terminal clawlike spine being the longest and the others decreasing in proximal direction. Each exposed segment bears two spines of apparently somewhat different length which all curve inward. Of the next swimming leg about one segment less protrudes and the segments are also shorter, the exposed part being thereby shorter by one sixth than that of the preceding leg. The fourth pair is shorter than the second by at least one third; its segments, however, are broader than long by about one third, so that again five segments protrude.

The swimming legs are distinguished by great length and width; turned back they reach the beginning of the narrow part of the postabdomen (line of third postabdominal segment). The coxae of the legs have been seen only in outlines too faint and obscure for exact description. One of these is indicated on plate 38. The manducatory edges which are the most resistant parts of the gnathobases are also seen on plate 37,