conjecture, that by some they were supposed to be white pepper in a 
state of petrifaction, may also now be considered as belonging to this 
genus of echinites. 
. cylindrical and longitudinal sulcated body, Plate IV. Fig. 13 , 
is sometimes found among the fossils of Sheppey Island. Its figure is 
un oubtedly ambiguous, it having some appearance of a small branch 
° a t f Ge . ; }’ howev er, entertain very little doubt of its being part of 
an echimtal spine. 
kones and teeth of the echini are sometimes found 
ng the fossil remains of these animals. This has been doubted 
) some ; ut I have no hesitation in saying, that I have some of 
these fossils from Switzerland. 
LETTER VI. 
FOSSIL SHELLS ARRANGEMENT OF LAMARCK ADOPTED CHITON 
PATELLA FISSUREL LA EMARGINULA CREPIDULA CONCHO- 
LEPAS.... CALYPTRASA.... CONUS.... CYPRASA....OVULA....TEREBELLUM.... 
OLIVA....ANCILLA....VOLUTA....MITRA....COLUMBELLA....MARGINELLA 
••...CANCELLARIA NASSA PURPURA BUCCINUM EBURNA 
TEREBRA...DOLIUM...HARPA... CASSIS. ..STROMBUS...PTEROCERA.. ROS- 
LLAR1A... M UREX...FUSUS...P YRULA... FASCIOLA RI A... PLEUROTOM A. 
Notw ithstanding a e g^t degree of judgment 
illustrious Llnnseus, in his systematic arrangement of shells, it does not 
appear to be proper to adopt his divisions in the present work It must 
beheve, be admitted that many of his genera are too comprehensive i 
added to which, since the forming of his classification, several shells have 
been discovered, possessing characters which will not allow them to 
P aced under any of his genera. The latter circumstance has indeed 
