NOTICE OF PALEONTOLOGY OF NEW YORE. 199 



in two authentic species {L. flabellites and L. fanhriata) ^ and the muscular 

 impression of the ventral valve is quite like that of the same species. 



The exterior extremity of the cardinal process presents considerable 

 variety of aspect, when a large number of individuals are examuied. 

 In some of them this part, if stripped of the external callosity of pseudo- 

 deltidium, would have the main process bilobed, with a sinus a little 

 below the apex, and an accessory lobe on each side similar to some of 

 the species of Productus. 



The Tropidoleptus carinatus is the typical species of the genus. A 

 western form has been described under the name T. occidens. 



The relations of the Genus Vitulina are not fully established. The 

 shell-structure is punctate, with a papillose surface, a high area on the 

 ventral valve, with a large triangular fissure. The genus embraces a 

 single species, the Vitulina pustulosa. 



The author, both in the preface and the body of the volume, has made 

 acknowledgments to many gentlemen for their liberality in furnishing 

 specimens for study and illustration during the progress of the work. 

 Among those specially named are Dr. G. A. Williams, of Boonville, Mo.; 

 Dr. James Knapp, of Louisville, Ky. ; Dr. C. Rceminger, of Ann-Arbor, 

 Mich. ; Major S. S. Lyon, of Jeflfersonville, Ind. ; Mr. 0. St. John, of 

 Waterloo, Iowa; Col. E. Jewett, of Utica, N. Y.; Joseph Sullivant, 

 Esq., of Columbus, Ohio; the late Dr. Mann, of Milford, Ohio; Prof. 

 Weight, of Hamilton, and J. DeCew, Esq., of Cayuga, Canada West. 



A special tribute is paid to the late Ledyard Lincklaen, Esq., of Caze- 

 novia, with whom the author enjoyed an uninterrupted friendship of 

 many years, and who at all times liberally aided the progress of geologi- 

 cal investigation, and contributed to the State Museum and the Natural 

 History publications of the State. 



The drawings illustrating the species have all been made by Mr. R. P. 

 Whitfield and lithographed by Mr. F. J. Swinton, and the proof sheets 

 have been revised by Mr. John Paterson. 



Albany, December, 1866. 



