152 LIST OF OUR LOCAL BIRDS. 



species of orthoceratites present in this limestone, bnt 

 there are apparently at least from twenty-five to thirty 

 species, mostly new. There are probably over sixty 

 species of fossils in our immediate neighborhood in the 

 Wappinger limestone, hitherto pronounced unfossilifer- 

 ous. 



As a group, it is very probable that the orthoceratites 

 will prove to be of much interest to students of cephalo- 

 podic structure. 



There is in this group of orthoceratites a predomi- 

 nance (1) of curved forms, (2) of frequent or crowded 

 septa, (averaging, perhaps, eighteen or twenty to the 

 inch), (3) of marginal siphuncles (not a single central 

 siphon has yet appeared in the whole number, so far as 

 I recollect), (4) of proportionately very large siphuncles, 

 generally without any cone, (ft) of elliptical or oval cross- 

 sections, (6) of smooth shells. 



The facts here developed have already far outgrown 

 the limits of the serial contributions begun in the Amer- 

 ican Journal of Science. It is my present plan, there- 

 fore, that this series should be carried to completion by 

 giving general statements, covering the whole ground of 

 the stratigraphy and paleontology, accompanied by 

 illustrated, descriptions of some of the more character- 

 istic fossils. The complete details, with copious plates 

 and maps, I hope to be able to present in the form of a 

 book as soon as the task of working up the mass of ma- 

 terial on my hands and the notes in my field-books can 

 be completed. 



APRIL 9, 1884— TWENTY-FIFTH STATED MEETING. 



Prof. W. B. Dwight, chairman, presiding ; six mem- 

 bers present 



Messrs. Arnold, Cooley, and Dwight exhibited, under 

 the microscope, specimens of rock-sections, crystals of 



104 



