Page:The Eurypterida of New York Volume 1.pdf/208

 markings like those of  but that "the shape of the carapace and the position of the eyes are so totally different that the two species can be distinguished very readily." As a matter of fact, the proportions of the carapace and the positions of the eyes are quite the same in both specimens [see under Measurements].

In the same publication Pohlman added several "new species" of Pterygotus to those before described from the Buffalo waterlimes by Grote & Pitt, increasing the number to a half dozen, all of which are synonyms of  save one. This latter was described by Pohlman as. It is based on a single postabdomen, in relief and counterpart, now in the Museum of the Buffalo Society. The two were combined in one figure, here copied [text fig. 40]. This figure illustrates the three principal characters of the specimen, viz, the bladelike extensions of the postlateral angles of the segments, the apparent globosity of the "telson" which gave the species its name and the coarsely pustulate sculpturing.

This "telson" [ pl. 24, fig. 1] has, at first glance, the features ascribed to it by Pohlman. It appears to have a round outline; the upper and lower plates have separated and a thick mass of matrix lies between them, suggesting the globose character attributed to it. But such a "telson" would have compelled this unfortunate creature to drag, like a member of an old-time chain gang, a cannon ball after him all his life. This structure