THE EURYPTERIDA OF NEW YORK IQ 
the chapters on the phylogeny and taxonomic position of the eurypterids. 
Holm had for the subject of his investigations the same Eurypterus 
fischeri from Oesel that had already been studied by Nieszkowski and 
‘Schmidt, and he succeeded by most clever manipulation in isolating the 
chitinous test of the animal which at Oesel is not metamorphosed into a 
carbonaceous film as in other localities, and was able to elaborate its organi- 
zation in such detail that E. fischeri has really become the most com- 
pletely known of all extinct animals, and our exact knowledge of it is quite 
comparable with that of its recent relatives. By comparison with Limulus 
the differences in the appendages of the first and second sternites were 
referred to their proper sexes. Many details of structure were discovered, 
such as the minute chelicerae, the epicoxite of certain coxal segments, the 
endostoma of the posterior margin of the mouth, the connection of the 
metastoma with the gnathobase, the clasping organ of the second endo- 
gnathite of the male, the originally composite nature of the metastoma, 
corresponding to the chilaria of Limulus and the interior tubular processes 
of the female opercular appendage. This work served to bring out with still 
greater force the numerous homologies and consequent close relationship 
of the eurypterids to Limulus. 
A comprehensive review of the more important of these discoveries 
with the status of the classification of the merostomes, was: given in 
1900 by Clarke in the chapter Eurypterida, Eastman’s English edition of 
Zittel’s Textbook of Palaeontology, where note was also taken of the 
ontogeny of Eurypterus. 
In 1900 also there appeared C. E. Beecher’s reconstruction of the 
giant Stylonurus excelsior Hall (which he preferred to call 
S. lacoanus) from the Catskill beds and in the next year the same 
author announced the discovery of a true eurypterid (Strabops 
thacheri) from the Cambric of Missouri, the only eurypterid from 
that fauna thus far known. 
At this date, aside from the few scattered individuals discovered in 
the Clinton and Manlius (Siluric), Portage and Catskill (Devonic) beds 
