ANCIENT WATER LEVELS OP CHAMPLAIN-HUDSON VALLEYS 217 



thing becomes gradually extended in a generic sense to pheno- 

 mena which in the later stage of critical classification appears 

 to have been given too extended a meaning, if It has not in a 

 premature broad generalization been made to embrace pheno- 

 mena which in the later stage of critical classification apper- 

 tain to a different system of distribution in time and space. 

 Quite often, owing to the limits placed on the choice of terms, 

 it is discovered that the namie itself has been preoccupied by 

 use for a very different object. In short the history of many 

 scientific names is somewhat as followis. 



In the so called natural history sciences names are first given 

 with the purpose of defining exactly some object, be it fish, 

 plant, land form or terrane. Being the type of its kind, similar 

 objects having some essential likeness, structure, form, mode 

 or time of occurrence are grouped with it under the same name. 

 As nature in her prodigality never exactly reproduces her crea- 

 tions, some of the objects present differences of one sort, some 

 of another, so that the name inevitably comes to have a broad- 

 ened and weakened meaning in proportion to the number of 

 occurrences which it is construed to designate. In time it thus 

 loses its original definite meaning and being replaced here and 

 there by terms of more accurate definition falls gradually into 

 disuse. Its friends may endeavor to save it either in its origi- 

 nal sense or with a restricted meaning in some respects dif- 

 ferent from its original use; but it has now lost its chief 

 value as a scientific name since it is ever a source of confusion 

 to the reader who has tO' carry in his mind, if he knows his 

 subject, the fluctuating values of the word in the different 

 periods of its history. In all this, scientific terms but exem- 

 plify those laws of use and disuse to which any words of the 

 language are subject. The names which have been introduced 

 for the fossiliferous marine deposits described in this report 

 appear at present to be under the operation of these laws. The 

 term "Albany Clays" specifically applied to the glacial rock- 

 flours of the Hudson valley north and south of Albany in 1846 

 antedates the name Albany since given by Texan geologists to cer- 

 tain carboniferous beds in Texas. 



