108 Observations Concerning Fossil Organic Remains. 



Desiderata in Geology. 



That some geologist will prepare with care, a systematic 

 description, by means of which we can determine the gene- 

 ra and species to which fossil remains, both vegetable and 

 animal, belong. The materials for such a work exist ; but 

 are distributed through a great variety of works ; as those of 

 Cuvier and Brongniart, of Parkinson, of Sternberg, of 

 Steinhauer, of Schlottheim and others. As far as I am ac- 

 quainted, there does not exist a systematic catalogue of this 

 nature; by which we can obtain an exact determuialion of 

 the species, or by which we should be conducted to a knowl- 

 edge of their resemblance to the animals and plants of the 

 present day. Such a system would teach us also, which of 

 the classes, orders, and families of organic bodies, present 

 the greatest number of analogies with living beings; and in 

 what proportion the number of the genera and species aug- 

 ment, as the deposits in which they are contained, become 

 more recent. 



The author of such a work, should be equally well versed 

 in geology, as in botany and comparative anatomy; for with- 

 out such an union of knowledge, his work would always be 

 defe<.'tive in those scientific details and general conclusions, 

 which ought to belong to it. 



With the necessary knowledge, he would be enabled to 

 make a just comparison of fossil remains among each other, 

 and with those at present existing in our lakes, rivers, and 

 seas ; from which would result the complete determination 

 of the similarity and dissimilarity, which may and ought to 

 exist in relation to this subject. 



From his geological knowledge he would be able to dis- 

 tinguish precisely to what extent, the order observed in the 

 superposition of transition, secondary and tertiary forma- 

 tions, is in harmony with those analogies with which the 

 types of the formations present him. By these researches 

 he would perceive if these types succeed each other in a 

 regular manner : — after the grayvvacke passing through the 

 black limestone of the transition, the sandstone of the coal 

 formation, the alpine limestone, the chalk ; from thence to 

 the tertiary gypsum, lacustrine formation ; and finally from 

 the diluvial deposits, to those of the alluvion : he would be 

 in a condition to demonstrate whether these types succeed 

 each other in the order which has been adopted in the sys- 



