REPORT OF THE DIRECTOR IQIO 29 



IMuseuni of Comparative Zoology, Cambridge, through Dr Sam- 

 uel Henshaw 



The Peter Redpath ^tuseum, McGill University, through Dr 

 Frank D. Adams 



Dr E. M. Kindle, Washington 



Prof. Stuart Weller, Chicago 



Dr Mark E. Reed, Buffalo 



Mr Irving P. Bishop, Buffalo 



Dr August F. Foerste, Dayton 



Mr Fred Braun, Brooklyn 



The illustrations in the work are from drawings skilfully ren- 

 dered by George S. Barkentin ; many of them, especially the restor- 

 ations and stages of immature growth, are based on Doctor Ruede- 

 mann's sketches and camera drawings. 



The eurypterid colonies of the New York Siluric are very dis- 

 tinctly 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 partly 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), v 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 Doctor Ruedemann. From 

 this time until the completion of the construction work referred 

 to Mr H. C. Wardell was almost continuously engaged in acquir- 

 ing these fossils and when the work was done the rock exposure 

 was left with a vertical face, so that no further product is now 

 available. In this eastern region of New York State the Salina 

 formation is without salt deposits, but the Otisville basin doubtless 

 antedated these deposits in central New York and is assignable to 

 an early part of the Salina stage. 



Colony P, or the Pittsford pool, is embedded in a black shale for- 

 mation which has never been exposed in any natural outcrops. As 

 we have observed, the rock was first brought to light by excavations 

 made in the deepening of the Erie canal in 1895 and the outcrops 

 were soon after covered by the riprap construction of the canal lin- 

 ing and so remain. Extensive collections of material were made by 

 Mr Clifton J. Sarle ; these were subsequently increased by the work 

 of ]\Iessrs D. D. Luther. H. C. Wardell and Fred Braun. The op- 

 portunity of further acquisitions from this fauna rests with the fu- 

 ture and depends on possible new excavations in the progress of 

 public improvements. 



Colony li, or the Herkimer pool, has been long exploited. It 

 lies above the horizon of the salt and its localities are in the vicinity 

 of Jerusalem Hill, Clayville, Sauquoit and Waterville. The most 



