CORRELATION OF STRATA. evil 
Gastropods. 287 species, contained in 46 genera, of which 149 species and 41 genera 
have been found in Minnesota. 30 of the Minnesota species occur in New York or 
Canada. The large genera, containing 4 or more species, are as follows: 
A ChimlalCellll airereteterepeberelotetercierereietale 13 species. IBTOS Citta Sh po.ne doodooDrODOpoane 13 species. 
SOG) <sosdooons6onucodoodsd6 7 species. HE} OGOMM ANG ayer steele hedelelehetessfete/oieesyal ete 6 species. 
(Ohprnali@sonpoonndocdsoogcus BHoK 7 species. JEIOTNOWONEysSo0005 oqo000G0n000 10 species. 
JEON VAD ME so 0c0eboes cacccone 8 species. Helicotoma....... Adododcopeacd 10 species. 
UME) Gduoo goog dobacaAandaS 6 species. WAGIDRE oa! sooacsdsosu0Ds0000 7 species. 
IBGE AIS onagoosode doaceeuesodd 18 species. = - WPOGKOAEME 550005 500b00000000 13 species. 
Salpingostoma................. 4 species. IDMINGHNEs cosa npn ba0D.d0N0DGD0 CO 6 species. 
Conradellanerrcrscecrecieccieveretere 10 species. GiyMOMEM Arsetore eyeleteleielaitsioleleleiaterelal= 4 species. 
Bellerophonsepcseeeererieteree cs 11 species. (Ci @lom@ritin?6ansancc0cndosq0K06 1] species. 
(CaninaropsiSmenmereicer cmc r 6 species. IBM sco dobGcace copa boca cdae 11 species. 
Raphistomina................. 4 species. Ghillomlitiioc se oageedn goo ndaooe 9 species. 
IDM DNNOR Ho sontoo cobou.oDCEdS 38 species. Fusispira..... Hanon eeasonease 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. 
Cephalopods. 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: 
@amerocerasiy. oerirereieere 4 species. (ChAIOCOHE Sacaogogddndb on acoan 11 species. 
ER rip LOCELAS ser etaoi-cisaserse ie ore 5 species. COMPACTS csoachongocasdan sec 12 species. 
Oncoceraswamcceeee eee 6 species. 
Ostracods. 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: 
enerdittellare.ascsencieercoss 5 species. iPahinlieonsdoededsaqooséoaboos 9 species. 
Schntidtellan yc .. cesses nce 6 species. DOA Mid cogs ocaacosHneencc 5 species. 
A ANCHUbES eran evsoeicietieioks siete 7 species. Micranellateeee cere 4 species. 
PETAL Lell aleeemlopereeeiseieievereietoreres 5 species. ES By hoCypri Seems sreel-fereielatatelteierels 4 species. 
Of these genera two have not their full complement in Minnesota (Leperditella, and 
Bythocypris, 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. 
Trilobites. 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 Pterygometopus, 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 stratigraphic designations are generally employed in assigning the fossils to 
their respective geologic horizons. Thus the limestones of the Stones River group are in 
