GEOLOGY. 283 



tions of New York will not afford more than sixty species, twenty- 

 seven of which have been found in a space not exceeding 100 feet 

 square. The number of species that were known in the State of 

 New York, previous to the beginning of the geological survey, 

 did not exceed four or five. Now about sixty species have been 

 ascertained. Prof. Hall mentioned the fact, that all the crinoids of 

 the lower silurian rocks, with the exception of one species, have five 

 pelvic plates, and we never find one with three, or any other number 

 of these plates, before we reach the highest deposits. In Tennessee 

 the crinoids are so abundant, that Prof. Troost states that he had been 

 able to collect some 300 or 400 good specimens of 7 or 8 different 

 species in a single morning. In relation to the abundance of these 

 fossils in the United States, Prof. Agassiz remarked, that it is not, 

 perhaps, sufficiently appreciated of what importance and of what im- 

 mense value the study of these fossil crinoids may be for the progress 

 of palaeontology. American students should be proud of these mate- 

 rials, by which they will be able to throw so much light upon these 

 almost extinct families by their personal investigations, which will not 

 only render them independent of the paleontologist from abroad for 

 information with regard to the succession of types, and the full illus- 

 tration of these structures, but really afford correct standards for com- 

 parison. It is the more desirable that all these fossils should be made 

 known, as the family of crinoids is so reduced in our days that we 

 can form no idea of the living animals of that group, of their diver- 

 sity of form, modification of character, and peculiarity of position, 

 from the living type only. He doubted whether the number of 

 crinoid heads of all species found in Europe, now existing in the mu- 

 seums of Europe, is one third the number of those which have been 

 found by a single gentleman in Tennessee in one morning. Now 

 with such materials, consider what precise and what minute investiga- 

 tions could be made. And if these facts could be once fully ascer- 

 tained and well illustrated, there is no doubt that the series of crinoids, 

 and their succession in former ages, will be established from American 

 standards, and will no longer rest upon the European evidence, which 

 has often been derived from the examination of small fragments of 

 those ancient fossils, found in unconnected basins for the most part, so 

 that their geological succession could be ascertained only with great 

 doubt and difficulty. In conclusion, Prof. Agassiz would venture to 

 say, that geologists who have had any opportunity to compare the 

 position of the ancient rocks on this continent with the corresponding 

 deposits of Europe, would agree with him in saying that the geology 

 proper, the stratography of this continent, will afford the same pre- 

 cise and well-authenticated standards for the appreciation of the order 

 of succession of rocks, as fossils will for the order of succession of 

 living beings. 



THE FOSSIL BOVINE ANIMALS OF SCANDINAVIA. 



PROF. NILSSOX, of Lund, in his " Skandin's Daggdjur" has an ac- 

 count of the bovine animals of Scandinavia, in which he makes some 



