300 NEW YORK STATE MUSEUM 
and shorter than that indicated by the sternite described above. In euryp- 
terids of the type of Eusarcus scorpionis Grote and Pitt, 
Carcinosoma newlini Claypole, Echinognathus cleve- 
landi Walcott, Eurypterus punctatus Salter, E. scor- 
pioides Woodward, E. scoticus 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 pro- 
vided 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. crt. pl. 12, fig. 5; 
here pl. 46, fig. 15] and referred to in the explanation of his plate as “ Doli- 
chopterus?? 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. 
Stylonurus myops Clarke 
Plates 51, 52, 53, figures I-s, 7 
Eurypterus myops Clarke. N. Y. State Mus. Bul. 107. 1907. p. 306, pl. 6, 
fig. 1-5 
Eurypterus maria Clarke. Ibid. pl. 3, fig. 6 
Eurypterus or Pterygotus. Ibid. pl. 6, fig. 8 
Segments and joints of Eurypterus, Hughmilleria, etc. Jbid. pl. 8, fig. 4 
In the preliminary note on the Otisville fauna this species was con- 
sidered as being ‘‘ in many respects a diminutive expression of Euryp- 
terus pittsfordensis 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. 
