of North America with those of Europe. 229 



Catenipora escharoides. — This species in all its varieties of 

 form is confined to the Clinton and Niagara groups of New York. 

 I have taken some pains to ascertain the facts m relation to 

 the Caledonia specimen cited by Verneuil, as received from Col. 

 Jewett. It proves to have been obtained at a place even higher 

 in the series than Caledonia, but the mass was a transported block 

 of the Niagara limestone, such as are often found either at the 

 base of the terrace formed by the Corniferous limestone or in the 

 valley along the base of the Hamilton group ; the latter position 

 is the one in which the specimen in question was obtained. 



It is not for a single species that we care to contend, neither its 

 identity nor geological position, but the integrity of the whole sys- 

 tem depends on maintaining the truth under all circumstances. 

 The views I advanced some years since in reference to the geo- 

 logical position of the Catenipora have never been controverted 

 by the production of a specimen from any higher position than 

 the Niagara group. 



There are among the list given by M. de Verneuil, several other 

 species the identity, and geological range of which we feel dis- 

 posed to question, but at present we have indicated only those of 

 which there can be no doubt. We feel conscious that this sub- 

 ject may be viewed and treated in two extremes. On the one 

 hand there are, and have always been, those who consider the 

 species of different beds as identical when they bear some gene- 

 ral resemblance to each other ; on the other hand there are a few, 

 who seeing the evil of this course have gone to the other extreme, 

 and regard a priori species from different beds as distinct. We 

 confess that we have more confidence in the latter than the for* 

 nier course, though we cannot fully agree with the practice. We 

 do not hesitate to say, that a difference between similar forms from 

 different geological stages is to be regarded as of more import- 

 ance than when the specimens are from the same bed. It not 

 infrequently happens that these slight obvious differences of spe- 

 cimens from different beds, prove to be connected with other and 

 more important differences which were not obvious on first in- 

 spection, and which are often developed by an examination of tiie 

 interior of the fossil. 



In these respects M. de Verneuil pursues an intermediate course, 

 w ith, as it appears to us, a leaning towards the previous opinions 

 and views of geologists and palaeontologists, which his own 

 acute powers of observation so often prove to be erroneous or 

 partial. In thus place we may mention loo the practice of refer- 

 nn g to previously established genera all the fossil types. This 

 has been so much the practice, that little progress has been made 

 in just discrimination till within a few years past. To show how 

 for this opinion or prejudice has prevailed, we need cite only the 

 genus Productus which for a Ions: time included all fossils of this 





