CHAPTER VIII. 



TIIK LOWEB SILURIAN TRTLOBITI 



< >F MINNESOTA. 



MCKK. 



tNTBODUCTION. 



trilohites have long invited the attention of observers, the curiosity of the 

 novice, and the mo-t intelligent scrutiny of the student. Murli of this interest lies 

 in the frequent beauty nf their preservation, their abundance, their complication of 

 structure. :ind. no doubt, largely in the fact that the organic plan upon which they 

 are const ni' n^ -ince extinct or only obscurely recognizable among their 



living descendants. It has been for the paleontologist to elucidate not only the 

 various modifications of this plan of structure, but to demonstrate the anatomy both 

 of their hard ami soft parts, their ajterations of form in the process of development 

 from infancy to old age, the rise, progress and decline through time of subsidiary 

 structural type-. For this work science acknowledges its obligation to the pioneer 

 investigations of Ihilman, Brongniart, I'rKay, Green, Pander, Kmmrich and 

 Burmeister; to those of McCoy, Salter and Wpodward upon the species of Great 

 Britain: of lieyrich. Corda. Barrande. Ka\-er. .\o\.ik upon those of Germany and 

 Bohemia; of de Verneuil. Houault, I'.ain.i-. <l hlert. Mergeron upon tbo^e of F'rance; 

 of Meneghini upon the Sicilian -peri.-; of l';u,<li" ko\\-ki. KichwaM. Schmidt 



on the lt'u--ian species; Angelin. Holm in Scandinavia, and Hall. Ford. W;ilcott. 



hew and liceclier in North America : a li-t to \\ Inch many name- nii^ht be added. 



The Trilobitos have proved of tir.-t importance to the stratigraphical KC"'"K' s t 

 as indices of geological age, and every ne -of nr .n- emphasi/es the 



importance of their various modifications to the student who Im-ic- hii 

 primarily with the structure of the earth and the correlation of the early sedimen- 

 tary de To the names above given we should append fho-r ..f : ,toi- 

 who have apprehended the trilobites mainly from this point of vi< rad. 



Kmmons. .Murchison. F. and A. l.'nemer. Linnaron. I'ame-. Hilling-. Wbitl;- 



,-, 



