SIXTH REPORT OF THE DIRECTOR ICjOO, 41 



2 The black Pittsford shale of the same Salina formation which 

 was exposed only by operations in widening the Erie canal, has 

 no known surface outcrop. All the remarkable specimens recovered 

 here were taken when the rock was fresh and there is little hope 

 of adding to this material until the formation is again opened by 

 civic improvements. 



3 The historic localities of eurypterids in Herkimer county, in 

 the region from Sauquoit to> Wheelock's hill, have been so care- 

 fully searched that even the stone walls of the region have been 

 quite fully overhauled. There are no known outcrops of the water- 

 limes in this region that now promise very much additional ma- 

 terial or knowledge. Last year an old barn was found near Crane's 

 Corners, whose foundation wall was largely composed of thin 

 waterlime Eurypterus slabs taken from an outcrop no longer ac- 

 cessible. This foundation we removed without disturbing the build- 

 ing, replacing it with concrete as the removal progressed and it 

 seems probable that the large material thus acquired is the last 

 extensive series of these fossils to be hoped for from this region 

 for some years to come. 



4 The black shales in the Shawangunk grits at Otisville, 

 Orange co., from which the very remarkable and extensive 

 series of development stages were derived a few years ago, 

 are now no longer exposed. These were shown mostly in a 

 quarry where the sandstone was being torn out for construction 

 of a branch of the Erie Railroad. That work is now finished and 

 the sandstone wall stands sheer and steep with the thin Euryp- 

 terus shale beds tight in between its layers. 



Aside from these four occurrences, specially noteworthy be- 

 cause of the abundance of their specimens, there are occasional 

 examples to be found along the line of Salina outcrops in western 

 New York, as at Union Springs, but these are rare and usually 

 individual occurrences. 



The monograph on these fossils is now brought to completion 

 and early publication is hoped for. 



Herein, in the chapter on morphology, a restoration of the 

 muscular system is attempted and evidence brought forward in 

 support of the view that the scales of the integument are muscle 

 scars ; the structure of the compound eye of Pterygotus is recog- 

 nized as consisting of an outer smooth cornea with an inner system 

 of papillary prolongations of the cornea serving as lenses, and 

 thereby the homology of the eye of Pterygotus with that of 



