CORRELATION OF STKATA. CV11 



Oialropodt. 287 specie*, contained in 4fl genera, of which 149 species and 41 genera 

 have been found in Minnesota. 80 of the Minnesota species occur in New York or 

 Canada. The large genera, containing 4 or more species, are as follows: 



Archinacella 13 species. Llo*plra 13 specie*. 



. 7 species. Eoloniarla. 8 species. 



Cyrtolltes.. 7 species. Ilnnuotoma. 10 species. 



Protowarthla.... 8 species. IMIcotoma. lOspecles. 



TetraooU species. Maclurea 7 species. 



Bacanla 18 species. Trocbonema 13 species. 



SalplDgoMtoma. 4 species. Euoema 6 species. 



Uooradella 10 species. Gyronema. 4 species. 



Bellerophoo 11 species. Cyclonema. 11 species. 



Carinarupsls 6 species. Holupea. llspecles. 



Raphlstonilna .. 4 specie*. Subulltes 8 specie*. 



Lophosplra. 38 species. Kuslsplra 10 species. 



Of the 242 species contained in the above 24 large genera, 125 species and all the 

 genera are represented in Minnesota. 45 species are contained in 22 smaller genera; of 

 these 24 species and 17 genera are represented in Minnesota. 



Cephalojxxti. 49 species, all occurring in Minnesota. 15 of these have been found 

 in New York or Canada. 38 species are contained in 5 large genera, and 11 in 8 smaller 

 genera, making 13 genera in all. The large genera, containing 4 or more species, are: 



Cameroceras 4 species. Cjrrtoceras llspecles. 



Trlptoceras 5 species. Ortboceras 12 species. 



Oococeras. species. 



Ostracodt. 67 species, of which 5 have not been found in Minnesota. Only one of 

 these has been reported from New York and Canada. The 8 large genera, having 4 or 

 more species, are the following: 



Leperditella 6 species. Prlmltla 8 species. 



Schmldtella. 6 species. Eurycbllloa 6 specie*. 



Aparchites 7 species. Dlcranella. 4 species. 



Prlmltlella 5 species. Uythocyprls 4 species. 



Of these genera two have not their full complement in Minnesota (Leperdifella, and 

 Hylhocypris, each 3 in Minn.), leaving 42 species in the state contained in 8 genera, and 

 36 species contained in 6 large genera. The total genera of ostracods are 22. The other 

 14 genera contain 22 species. 



Trilobite*. 40 species, of which 8 have not yet been found in Minnesota. Of the 32 

 species, 17 have been found in New York and 7 have been reported from Canada. There 

 are 20 species of trilobites which are common to Minnesota, New York and Canada. 

 Only two genera contain as many as 4 species, viz.: Isotelus, 4, and Pterygometoput, 4; 

 but one species of the latter is absent from Minnesota. The total number of genera is 24, 

 but three of these have not been found in Minnesota. 



In the descriptive portions of the volume, excepting the last chapter (Gastropoda), 

 temporary strati graphic designations are generally employed in assigning the fossils to 

 their respective geologic horizons. Thus the limestones of the Stones River group are in 



