10 



Entomolithus Paradoxus, proposed by Linne, was ap- 

 plied to all the fossil remains, which in their general 

 appearance bore any resemblance to that found at 

 Dudley, and which he first described under that 

 name. The confusion, therefore, which existed in 

 this department of natural science, may readily be 

 imagined; especially, as the species rapidly multi- 

 plied, when they were supposed to throw some rays 

 of light on certain obscure geological phenomena. 

 Soon after the appearance of Professor Brongniart's 

 excellent work, the attention of other naturalists was 

 directed to this neglected part of creation. The 

 most important memoir, on account of the number of 

 species, well figured and described in it, is one by 

 Dr. E. W. Dalmann, published in the Transactions of 

 the Swedish Academy, for 1826, There is also in 

 the Acts of the Royal Society, at Upsal, an excellent 

 paper on this subject by Professor Wahlenberg. 

 Our highly esteemed friend, Dr. James E. Dekay, 

 has also given in the first volume of the Annals of 

 the Lyceum of Natural History of New York, some 

 very interesting and ingenious observations on the 

 nature and the structure of the Trilobites, with a de- 

 scription of a new genus. These are the principal 

 authorities which have been consulted in arranging 

 the present work. 



Our object in the present undertaking being mere- 

 ly to give a monograph of the species of Trilobites 



which he is the director, will no doubt acknowledge that his 

 talents as a philosopher, are rivalled by his accomplishments as 

 ft gentleman. 



