Page:The Eurypterida of New York Volume 1.pdf/389

 Salter and  Salter and also those of  ." The reference to Hughmilleria in this connection appears to us especially significant, since the eyes show the distinct angulation on the inner side, so characteristic of that genus, and moreover fail to exhibit any signs of the facets, generally quite distinct in Pterygotus. It is quite possible that this specimen is a very large carapace of Hughmilleria partly doubled upon itself in front (of which there is evidence along a break); although on the other hand it must be conceded that the lateral eye is relatively larger than that of.

So far then as concerns this carapace  is an uncertain species, but unmistakable evidence of the presence of a true Pterygotus in the Pittsford shale is afforded by the free ramus of a chela, reproduced in plate 70, figure 3. Sarle has separated this and a metastoma [pl. 70, fig. 4] on the ground that they belong to coarse-scaled fragments that represent another species. Inasmuch as the carapace as a rule has a much finer sculpturing than the rest of the body (e. g. in ), there seems little ground to assume the presence of more than one species of Pterygotus in the Pittsford beds.

Judging from the ramus of the chelicera, this type was more closely related to  than to any other form, the latter species possessing the same rounding of the extremity of the ramus and similar form and direction of the teeth [pl. 77, fig. 6], the latter being still a little more rectangular upon the shaft than in.