182 PROCEEDINGS OF THE GEOLOGICAL society. [ Dec. 15, 
Messrs. Buckman and Strickland have made additions to the Stones- 
field slate shells in their work on the Geology of Cheltenham. These 
are all the authorities relating to the course of the great oolite in the 
middle and south of England. The testacea of these rocks in the 
north of England have been more fully illustrated, and the lists of 
Messrs. Phillips, Bean and Williamson contain a considerable number 
of species; but unfortunately the oolitic series of rocks beneath the 
Oxford oolite in Yorkshire constitute a great carboniferous deposit, 
which differs essentially both in its natural subdivisions and mineral 
character from the presumed parallel series in the middle and south 
of England. On this account the Yorkshire lists of shells have little 
more than a local value, masmuch as the particular stratum to which 
they are referred cannot with certainty be placed as the equivalent 
of a stratum whose position in the series is elsewhere determined. 
Further information respecting the shells of this epoch can only be 
obtained by referrmg to the works of Roemer, Goldfuss, Bronn, 
Dunker, D’Archiac, Deslongchamps, &c., where a large number of 
foreign oolitic shells are figured and described. It would seem that 
there attaches a degree of reproach to us that the shells of a forma- 
tion which engaged the attention of the fathers of geology in the 
earliest infancy of the science should still remain perhaps less gene- 
rally known than those of any other fossiliferous series in the king- 
dom. In the hope that this little memoir may somewhat assist in 
remedying this defect, I have ventured to submit the accompanymg 
list of species and observations. The district to which these 
remarks apply is very small, having a radius of only three miles. 
Nevertheless within this limited space, very many species, and even 
several genera, are found which are new to science. Possibly some 
few of these may be described in foreign authorities with which I 
am not acquainted ; it is not likely, however, that their number is 
considerable. In fact, when collating foreign oolitic forms, it is re- 
markable how few are found identical with our own ;—there is so 
strong a family resemblance that at first we feel confident that we 
shall establish a specific relationship ; but a closer scrutiny undeceives 
us, and eventually we feel surprised at the small number which we 
can call our own. In some instances errors are corrected into which 
others have fallen from describing imperfect specimens, or from un- 
acquaintance with the hinges of the bivalves ; nor is it unlikely that 
here also similar errors are committed from the same causes. The 
smallness of area has at least one advantage,—it enables us to exhibit 
the grouping or assemblage of contemporaneous species free from the 
doubt which must sometimes exist with regard to fossils collected 
over a more extensive tract of country. The results of this examina- 
tion, it is trusted, are such as will afford some curious information 
with respect to the proportion and diffusion of the Zoophagous tribes. 
Until very recently an opinion has prevailed that we might in vain 
look for the carnivorous Trachelipods im rocks of such antiquity as 
the great oolite, or that they were extremely few, and that it was 
only on the extinction of those two great families of Cephalopods, 
the Ammonites and Belemnites, that this class of mollusks first ap- 
