422 APPENDIX. 



pletely converted into silex, known by the name of 

 horse-foot, found on lot No. 69, Cayuga reservation, and 

 presented me by D. Clinton, Esq. This specimen has 

 never been described by any writer to my knowledge. 



Serpulite. 



A fragment of a Serpula, if extended upon a straight 

 line, woald measure about 10 inches; this is a carbonate 

 of lime, and was found in Coeyman's patent, near Al- 

 bany. 



Orthocerite. 



First Species. From seven to eight inches in length, 

 and one and a quarter inch to two in diameter at the 

 base; straight, and not turbinated; tapering from the 

 broad end to a sharp pointed top, like a straight horn, 

 (from whence its name.) They are chambered from bot- 

 tom to top, and have a Siphunculus or pipe of Cottcam- 

 meration from chamber to chamber pipe central. 



These specimens I obtained from Sullivan County, 

 New- York. In your valuable collection you have seve- 

 ral very distinct and well marked, which I believe are 

 from Jefferson animal extinct. 



Linnaeus ranks them in his system as Nautilus Ortho- 

 cera. 



They are generally casts of stone or replacements of 

 sparry matter; sometimes fragments of shells may be 

 seen on them. 



Second Species. Lituus. This exactly resembles a 

 bishop's crozier in shape, has a long stem, cylindrical 

 one end whereof has a.spiral turn ; this shell is soft and 

 easily fractured. 



