28 



these, however, in our opinion, are more vague and 

 uncertain than most of the others. The genus, how- 

 ever, we think may be readily identified, after becom- 

 ing- familiar with one well characterized species. 

 The general aspect of the buckler is peculiar the 

 body is not so depressed as in most other genera, and 

 the lateral lobes are destitute of all membranaceous 

 expansion. 



To the genus Calymene, belongs the celebrated 

 Dudley fossil, called Entomolithus paradoxus by Blu- 

 menbach, but which is not the same organic relic, 

 to which Linne applied that name. 



This genus includes a great number of species, and 

 though some of them are said to be found in different 

 and distant parts of the globe, they are according to 

 our limited observation, for the most part confined, 

 like recent species of animals, to particular districts. 

 The C. polytoma, C. pulchella, C. bellatula, C. con- 

 cinna, C. sclerops, and the C. punctata, all finely 

 figured by Professor Dalman, and which are found 

 in Sweden, have not yet been noticed in any part of 

 North America.* 



CALYMENE BLUMENBACHII. Brongniart. Cast No. 1. 



Clypeo rotundato, tuberculis sex distinctis in 

 ironte; oculis in genis emintissimis; corpore tuber- 

 culato. 



* See the valuable and extensive communication of J. W. 

 Dalman, M. D , on the Trilobites, in the Transactions of the- 

 Swedish Academy for 1820, part 2d. - 



