PALEONTOLOGIC CONTRIBUTIONS IOQ. 



doubt from the shape and curvature of the spine that it is one of the 

 series of spines attached to the underside of the walking legs (see 

 N. Y. State Mus. Mem. 14, pi. 57, fig. 4). If that is the case, then 

 the corresponding leg must have been several feet long and the 

 entire specimen ranked in size with the largest eurypterids known. 



The spines on the leg of Echinognathus clevelandi, 

 which is the type of the species, are not furnished with scale mark- 

 ings but with longitudinal striae. It is therefore possible that we 

 have here before us another species of Echinognathus, but it is 

 also quite possible that the ridges formed by the striae, in mature 

 forms, break up into series of long scales and finally into irregular 

 scales, as we see them on the spine in question. This alternative 

 case is suggested by the shape and the arrangement of the scales. 



Another fossil referable, though with more doubt, to Echinog- 

 nathus, is a heart-shaped carbonaceous test, of which we have two 

 specimens, both from the Utica shale at Holland Patent, Oneida 

 county, N. Y. The larger (text fig. 36) one is about 68 mm wide 

 and 64 mm long, broadly heart-shaped with a deep notch in the 

 middle. The other, a slightly smaller specimen, shows evidence of 

 the body having been a rather thick plate. The larger specimen 

 exhibits in several places, as indicated in the figure, irregularly 

 scattered nodes or scalelike markings. From their general outline 

 these bodies, if eurypterid remains, must have been metastomas ; 

 and, if such, they indicate an undoubted relationship of Echinog- 

 nathus to Eusarcus, for only with the metastoma of that genus 

 can this plate be compared. Clarke and Ruedemann have pointed 

 out in Memoir 14 (p. 58-59) how characteristic the form of the 

 metastoma is of the different genera of the eurypterids. The short, 

 stout walking leg of Echinognathus is also well comparable with 

 that of Eusarcus, while on the other hand the rows of spines would 

 suggest relationship to Stylonurus. When it is remembered, how- 

 ever, that also Eusarcus scorpionis and, still more, 

 E . n e w 1 i n i have very long curved spines on their walking legs, 

 it is readily conceivable that we see before us in Echinognathus an 

 extreme development of this character of Eusarcus. 



These metastomas would also indicate for the species of 

 Echinognathus to which they belong, a size of a meter or more. 



There is also a large carbonaceous test (text fig. 37) in the 

 Utica shale material from Holland Patent which, though badly 

 flattened, answers very well for the carapace of a eurypterid, 

 resembling Eusarcus. It is trapezoidal in outline, with a broad 

 base and tapering to the narrow frontal side. At the corners of 



