PLATE LXXI. , 



PAGE. 



Figs, land 2 LOPHOSPIRA AUGUSTINA Billings sp 987 



Two figures of a rather large cast of the interior of the Minnesota form which we 

 refer to this species. Fig. 2 shows the filling of the umbilical perforation. 

 Maclurea bed of the Trenton group, Stewartsville, Minnesota. 



Figs. 3 and 4 LOPHOSPIRA AUGUSTINA var. MiNNESOTENsis U. and S 988 



3 A large specimen of this variety, from the same locality as the preceding. The 



outline restoration of the aperture may not be entirely correct. 



4 A smaller specimen, also a cast of the interior; from the same locality. The 



smallest two whorls are restored from another specimen. 



Figs. 5 to 7 HOKMOTOMA (?) MAJOR Hall sp 1018 



5 The last four whorls of a cast of the interior that we believe to belong to this 



species. Trenton group, Pike county, Missouri. Geological and Natural His- 

 tory Survey of Minnesota, Museum Register No. 7842. 



6 Outline of outer lip of same, showing the broad sinus or notch. 



7 Last two whorls of a specimen retaining part of the shell, but so ill preserved 



that not a trace of surface markings remains. The specimen is important, 

 however, because it shows the external character of the sutures. Maclurea bed 

 of the Trenton group, Olmsted county, Minn. Geological and Natural History 

 Survey of Minnesota, Mflseum Register No. 7485. 



