140 WHITFIELD. 



specimens used were referred at the time of their publication ; 

 and the last column, the locality from which they were ob- 

 tained, so far as known to the author. 



The specimens stated to belong to the Wisconsin State col- 

 lection, which was located at Madison, Wis., were mostly de- 

 stroyed by fire some years ago, when the state buildings at that 

 place were partially destroyed. Many of the Cretaceous fossils 

 (mostly bivalves) given as being at Trenton, N. J., were de- 

 stroyed by fire and water at the capitol at Trenton soon after 

 the publication of the first volume of the New Jersey Palaeon- 

 tology. 



Among the lamellibranchiate fossils in the State Museum at 

 Albany and in the American Museum of Natural History in 

 New York are many species, the authors of which are stated to 

 be " H. & W." These species and several genera were written 

 by R. P. Whitfield, under an agreement of joint authorship 

 with Prof James Hall, but published in an anonymous pam- 

 phlet entitled " Preliminary Notice of the Lamellibranchiate 

 Shells of the Upper Helderberg, Hamilton and Chemung 

 Groups, with Others from the Waverly Sandstones. (Prepar- 

 atory for the Palaeontology of New York.) Part 2." See the 

 initials, R. P. W., on pp. 84, 91, 93, of the pamphlet. The 

 species are not entered in this catalogue, but they and the gen- 

 era referred to will be found appended thereto. 



The writer commenced the compilation of this catalogue 

 many years ago, under the impression that it would be an aid 

 to other workers, to know where such specimens described and 

 figured in different publications were to be found, as he has 

 very often felt the need of such knowledge of forms which he 

 has needed to compare with, or refer to, in course of his own 

 work. 



A list of the abbreviations used for the institutions or collec- 

 tions and of those used for the geological formations will be 

 found appended. 



Each specimen was originally marked with a small emerald- 

 green paper ticket, to indicate that a drawing had been made 

 of it for publication. 



