Page:The Eurypterida of New York Volume 1.pdf/306

 and shorter than that indicated by the sternite described above. In eurypterids of the type of  Grote and Pitt,   Claypole,   Walcott,   Salter,   Woodward,   Laurie, etc., so far as material shows, the preabdomen is obese, the second pair of endognathites is the longest, and all four pairs with their spines are curved forward. In Stylonurus and the related genus, Drepanopterus, the fourth endognathites are without any elaborate development of spines, and in the former are greatly elongated. In Slimonia the first pair of endognathites is tactile, the succeeding three pairs are short, vary little in size and are all provided with small spines at the distal ends of the joints. In the Pterygotus the four pairs of endognathites are filiform, of nearly equal size and probably in all cases, spineless.

A metastoma of peculiar form, figured by Sarle [op. cit. pl. 12, fig. 5; here pl. 46, fig. 15] and referred to in the explanation of his plate as "Dolichopterus?? metastoma of an undetermined form," approaches in shape more closely the metastoma of Stylonurus than that of any other genus. It seems to us very probable that it also belongs to this species.

Clarke. N. Y. State Mus. Bul. 107. 1907. p. 306, pl. 6, fig. 1–5

Clarke. Ibid. pl. 3, fig. 6

or. Ibid. pl. 6, fig. 8

Segments and joints of Eurypterus, Hughmilleria, etc. Ibid. pl. 8, fig. 4

In the preliminary note on the Otisville fauna this species was considered as being "in many respects a diminutive expression of  Sarle, the head (all that is now known of it) being subquadrate, almost as much squared in front as behind, the eyes large, semicircular, subcentral and approximate and the ocellar mound developed in mature forms." The greatly enlarged collections from the same locality secured by the State Museum since the date of the preliminary paper, throw a different light on the generic relations of this species, and furnish the data for the following description.