- Columbia University, through Profs. A. W. Grabau and Jesse E. Hyde
- Museum of Comparative Zoology, Cambridge, through Dr Samuel Henshaw
- The Peter Redpath Museum, McGill University, through Dr Frank D. Adams
- Geological Survey of Canada, through Dr Percy E. Raymond
- Dr E. M. Kindle, Washington
- Prof. Stuart Weller, Chicago
- Prof. Gilbert van Ingen, Princeton
- Dr Mark E. Reed, Buffalo
- Mr Irving P. Bishop, Buffalo
- Dr August F. Foerste, Dayton, Ohio
- Mr Fred Braun, Brooklyn
The illustrations in the work are from drawings skilfully rendered by George S. Barkentin, many of them, especially the restorations and stages of immature growth, based on Dr Ruedemann's sketches and camera drawings.
***
The eurypterid colonies of the New York Siluric are very distinctly localized and of them we know two at the bottom of the Salina series or beneath the salt beds and two at the top of the series. These colonies were doubtless in part breeding pools in brackish waters, partly more open basins, restricted in extent by the limitations of favorable physical conditions.
Colony O, or the Otisville basin lying far eastward of the rest and on the borders of the Appalachian region, is embedded in an almost unlimited repetition of thin black shale between layers of heavy sandstone of the Shawangunk formation (Salina stage). In the construction of railroad improvements the rock wall here was broken down for ballast and while this work was in progress the eurypterid remains were detected by Dr Ruedemann. From this time on until the completion of the construction work referred to, Mr H. C. Wardell was almost continuously
