454 ON THE GEOLOGICAL RELATIONS, &C. 



same with madreporites, pentacrinites, eutomolites, 

 gryphites, pectines, anomiae, ostreae, patellae, ammo- 

 nites, and many more ; and there are not even predo- 

 minant associations of these. Conchologists them- 

 selves can extend this list, as I need not ; any cata- 

 logue will enlarge it. Crabs exist as far asunder as 

 the mountain limestone and the chalk. Crocodiles 

 are found in the lias, tlie oolithe, the green sand, 

 and the upper blue clay. Belemnites abound in the 

 chalk of Ireland, and are rare in that of England. 

 The exceptions are too abounding to permit of the 

 rule ; though I have given but a small number. 



It is quite time that geologists should review their 

 system, in this, as in far more, and correct their prac- 

 tice. Then, and not till then, shall we begin fairly to 

 study the history of the Earth ; and, in time, we shall 

 know the Truth ; the Truth itself, and the ever odious 

 truth that we have been in the wrong. Let shells be 

 used as aids, as far as they can : but if strata are to be 

 determined by shells alone, it will be the land of shells 

 and conchologists that will set the pattern of the earthy 

 as other lands and other conchologists, will, under 

 Breislak's remark, contest for other patterns. This is 

 riot geology ; and thus will Geology never be. 



I terminate this chapter by referring to the cata- 

 logues of conchologists as connected with the strata, 

 whether in this or in other countries. They will furnish 

 many facts of reference for much that has preceded : 

 but I could not, with any propriety, encumber this 

 work with them, The geological bearings of these 

 most important bodies in the history of the Earth 

 have been stated as far as I was enabled to do so 

 from the information in existence. 



