NOTES. 31^ 



NOTE ADDRESSED TO MES MEXER BY MR SALTER, 



OP THE GEOLOGICAL SURVEY, 



UPON THE CHAPTER ON " THE FISHES OF THE SILURIAN ROCKS, 

 UPPER AND LOWER." 



" As much of the reasoning in chapter vi. of the first edi- 

 tion is based upon the supposed occurrence of placoid fishes 

 in the Lower Silurian rocks of Wales, it is but right to re- 

 fer you to the disclaimer put forward by me in 1851, in the 

 seventh volume of the * Quarterly Geological JournaL' In 

 both the instances in which I am responsible, a hasty field 

 examination was unfortunately accepted and published, be- 

 fore sufficient time, or even a re-examination of such precious 

 and unique relics, had been allowed ; and, as in almost every 

 other case, the more haste the worse speed. The statements 

 of two eminent geologists could not of course be other than 

 good data for reasoning ; and hence the mistake. In point 

 of fact, the S. Welch fossil was a zoophyte, — greatly like a 

 fish defence, however ; and the N. Welch one a portion of a 

 trilobite ! I then examined the other reputed cases of fish 

 remains from Silurian strata, and in one, a plate of a Cysti- 

 dean animal from the Caradoc rock had been mistaken for a 

 dermal plate of a ganoid fish j in another (the celebrated Ces- 

 traciont tooth of the ' Edinburgh Review'), the species turned 

 out to be the Cochliodus ali/ormis (M'Coy), a mountain lime- 

 stone fossil common in the immediate neighbourhood of the 

 Silurian quarry, where it was picked up. Again, the frag- 

 ments attributed to fish in the Ludlow rocks, and mentioned 

 by Phillips and others, have invariably turned out to be 

 blackened portions of annelide tubes, or something else not 



