Page:The Eurypterida of New York Volume 1.pdf/159

 considered as indicative of a new genus and it is proposed to recognize this type under the name Strabops nov. gen., with  n. sp. as the type species. The generic name is in allusion to the inward turning or squinting of the eyes.

Two of the differential characters here cited, viz, the anterior position of the eyes and the absence of one somite, are not verified by the counterpart. The supposed eyes, which were represented as oblique ovate cavities with the visual surfaces apparently broken out [see original figure, copied here in text fig. 31], are small lumps of the underlying rock held in place by the overlapping fold which has formed near the frontal margin by a shoving of the specimen. These have been chiseled out on the counterpart and the surface of the folded part of the carapace exposed. The real eyes are seen in our specimen half way between the anterior and posterior edges, near the lateral margin. They are small and circular.

The other difference concerns the number of abdominal somites on the dorsal side, for the intaglio and the plaster cast therefrom seem to leave no doubt that Strabops agreed with the later eurypterids in having 12 segments. The 1st segment is for the greater part pushed under the carapace, and the next, the 1st in Beecher's figure, is shown only on the right side of the bent specimen; on the other side the bending of the abdomen has forced it back over the 3d tergite.

With these corrections of structure, Strabops stands still closer to the Siluric Eurypterus than it appeared to Beecher; in fact it is obvious that all the principal parts of eurypterid structure are already fully fixed in