482 Professor C. E. Beecher — On Stylonurus Lacoanus. 



remains of Pterygotiis anglicus, and on the evidence of the numerous 

 detached portions of this extinct genus, we are justified in concluding 

 that it attained a length of six feet and a breadth of nearly two feet 

 at the widest part of its body." This huge Merostome has been 

 found in the Lower Old Eed Sandstone of Scotland, at a horizon 

 nearly equivalent to the one furnishing the remains of Sfylonunis in 

 America. Thus what seem to be the two largest species of this class 

 were contemporaries, though not associates. 



Historical. 



The first specimen found in America that can be referred to the 

 genus Sttjloniirus was collected by the writer about 1870, and loaned 

 to Professor James Hall. It remained in his hands unnoticed until 

 1884, when he described it as Euryptenis Beecheri} The specimen 

 preserves the abdomen and portions of two of the large posterior 

 limbs. No species of Eurypterus known possessed such greatly 

 elongated limb joints, and there seems to be no good reason for not 

 referring it to Stylonuriis, in which there is a normal character. The 

 specimen of Stylonuriis Beeclieri is uncompressed, and apparently 

 retains the proportions of form and convexity as in life. On this 

 account it was of considerable importance in the restoration of the 

 larger species. 



In 1882 Hall was furnished with a plaster cast of the carapace of 

 a large arthropod by Dr. Cook, then State Geologist of New Jersey. 

 The original specimen was from the Catskill group at Andes, 

 Delaware County, New York, and had been sent to the museum 

 at Eutgers College, New Brunswick, New Jersey. Professor D. S. 

 Martin^ made the first reference to this species in some remarks 

 on "A New Eurypterid from the Catskill Group," before the New 

 York Academy of Sciences, October 16, 1882, an abstract of this 

 note appearing in the transactions of the same society some time 

 after June, 1883. In this abstract the species is neither described 

 nor figured, and Hall is not mentioned in any connection. Martin 

 states that he saw the specimen (= cast sent to Hall) in the State 

 Museum at Albany, and it bore the name Stylomurus excelsior 

 (evidently a misprint for Slylonurus). 



The next reference to this form in point of time and the first 

 publication of a generic and specific name, accompanied with 

 a, description and accurate illustration, was given by E. W. Claypole,' 

 in a paper read before the American Philosophical Society, Sept. 21, 

 1883, under the title " Note on a large Crustacean from the Catskill 

 Group of Pennsylvania." It is stated on the signature containing 

 this paper that it was printed Nov. 2, 1888. Claypole's description 



1 J. Hall, "Note on the Eurypteridge of the Devonian and Carboniferous 

 Formations of Pennsylvania" : Second Gaol. Siirv. Penn., PPP, 1884. 



2 D. S. Martin, "A New Eurypterid from the Catskill Group": Trans. N.Y. 

 Acad. Sci., vol. xi (1882-1883). 



3 E. W. Claypole, " Note on a large Crustacean from the Catskill Group of 

 Pennsylvania" : Proc. Amer. Phil. Soc, vol. sxi, April, 1883, to January, 1884. 



