310 MAN OF SCIENCE. 



side of pterichthys fully fifteen years ago. The greatest 

 of living ichthyologists, however, misled by a series of 

 specimens much less complete than mine, differed from 

 me in my conclusions ; and what I had represented as 

 the creature's under or abdominal side, he represented as 

 its upper or dorsal side ; while its actual upper side he 

 regarded as belonging to another, though closely allied, 

 genus. I had no opportunity, as he resided on the 

 Continent at the time, of submitting to him the specimens 

 on which I had founded ; though, at once certain of his 

 thorough candour and love of truth, and of the solidity 

 of my data, I felt confident that, in order to alter his 

 decision, it was but necessary that I should submit to 

 him my evidence. Meanwhile, however, the case was 

 regarded as settled against me ; and I found at least 

 one popular and very ingenious writer on geology, after 

 referring to my description of the pterichthys, going on 

 to say that, though graphic, it was not correct, and that 

 he himself could describe it at least more truthfully, if 

 not more vividly, than I had done. And then there 

 followed a description identical with that by which mine 

 had been supplanted. Five years had passed, when one 

 day our greatest British authority on fossil fishes, Sir 

 Philip Egerton, was struck, when passing an hour among 

 the ichthyic organisms of his princely collection, by the 

 appearance presented by a central plate in the cuirass of 

 the pterichthys. It is of a lozenge form ; and, occupy- 

 ing exactly such a place in the nether armature of the 

 creature as that occupied by the lozenge-shaped spot on 

 the ace of diamonds, it comes in contact with four other 

 plates that lie around it, and represent, so to speak, the 

 white portions of the card. And Sir Philip now found, 

 that instead of lying over, it lay under, the four con- 

 tiguous plates ; they overlapped it, instead of being over- 



