262 bulletin: museum of comparative zoology. 



County. Also in the neighborhood of Amsterdam. I haA'e better 

 collections from near Lake Ontario, on Sandy Creek, near Ellisburgh, 

 Jefferson County." 



Since receiving this letter I have visited all these localities, the fu-st 

 two of which were already familiar to me from previous work. There 

 can be no doubt that the last locality contains the typical Fusispira 

 fauna, for the strata there are of the very highest Trenton, just be-' 

 neath the Utica shale, and it is in the immediate vicinity of the places 

 from which the principal species of the Fusispira fauna were originally 

 described. The other two localities are located where only basal 

 Trenton strata are exposed. "The vicinity of Poland" probably 

 means the exposures between Poland and Newport, the localities of 

 the well-known Rathbone Brook section and the "Moshier quarry" 

 in the Leray-Black River. The lower part of the Trenton (Crypto- 

 lithus beds) in this section contains some layers with gastropods, but 

 I have found Fusispira here only in the Leray-Black River where it is 

 associated with a number of other gastropods in a large fauna (107). 



At Amsterdam the section is practically the same as at Poland. 

 Only the lower part of the Trenton is exposed, and it rests upon a very 

 small thickness of the Leray-Black River, which formation is not very 

 fossiliferous. If any members of the Fusispira fauna are found here, 

 they must be in a very different association from that in Minnesota, 

 and are certainly at a much lower horizon. 



The last place mentioned by Ulrich, is in New Jersey, at Jackson- 

 burg, where the formations present are equivalent to those at Amster- 

 dam and Poland in New York and the same remarks will apply to it. 

 Personally I am unable to see in the faunas of any of these localities 

 anything to suggest the Fusispira fauna of Minnesota and even if the 

 Fusispira fauna be there, the section in New York affords ample proof 

 that the Lower Trenton beds with Cryptolithus are below the typical 

 Trenton of Trenton Falls and the Fusispira fauna occurs in the Upper 

 Trenton beds, above the typical Trenton of the Trenton Falls section. 



The above discussion is necessary to justify my position in placing 

 the Prosser very much higher in the section than it is placed by other 

 writers. 



Central Pennsylvania. 



The section in central Pennsylvania at Bellefonte has been described 

 in outline by Professor Collie (100), and has lately been reinvestigated 

 at my suggestion by Mr. R. M. Field, in whose company I was able 



