PAGE. 



Figs. 31 to 33 HELICOTOMA SUBQUADBATA Ulrich 1033 



31 and 32 Lateral and basal views of a specimen. The central ridge in fig. 31 is probably 

 abnormal. 



33 Lateral view of another specimen from Murfreesboro, Tennessee, with rather 



obscure revolving lines on the vertical side. 



Figs. 34 to 38 HELICOTOMA DECLIVIS Safford 1036 



34 Upper side of a small but well preserved example of this sharply defined species. 



Lower division of the Stones Eiver group, Murfreesboro, Tennessee. 



35 to 38 Four views of an average specimen, from the same locality. Among the peculiar- 

 ities that should be especially noted, is the even slope of the umbilical cavity, 

 in the bottom of which the inner whorls are not distinguishable. 



Fig. 39 HELICOTOMA MARGINATA Ulrich 1036 



Upper side of a specimen adhering to a piece of the limestone matrix. Beneath 

 the figure, a line showing profile. Top of Richmond group, near Richmond, 

 Indiana. 



Figs 40 to 42 and 47 OPHILETINA SUBLAXA U. and S 1030 



40 Upper side and a section of the free whorl of a testiferous example of the typical 



form; from the Stones River group at Dixon, Illinois. 



41 Portion of the free whorl of same, x2, showing the surface markings from above. 



42 Upper side and section of free whorl of a silicifled specimen of the var. depressa, 



from Murfrees'boro, Tennessee. As may be seen at once by comparing the 

 transverse sections, the free whorl in this specimen, is narrower than in the 

 Illinois specimen. 



47 Portion of the upper side of the outer whorl of a specimen from Mineral Point, 



Wisconsin, x3. Geological and Natural History Survey of Minnesota, Museum 

 Register No. 7302. 



Figs. 43 to 46 OPHILETINA ANGULAKIS U. and S 1031 



43 to 46 Four views of the type of this species, x2. Phylloporina bed of the Black River 

 group, near Cannon Falls, Minnesota. 



Figs. 48 to 52 EccYLiosii'HALtrs CONTIGUUS Ulrich 1037 



48 Apertural view of a specimen having the inner whorls slightly raised above the 



plane of the outer one. Lower division of the Stones River group, Murfrees- 

 boro, Tennessee. 



49 and 50 Somewhat restored views of the upper and lower sides of a larger specimen. 



51 and 52 Two views of a small example having the inner whorls slightly depressed. 



Figs. 53 to 56 



Four views of three specimens of a totally unplaced gastropodous shell. Rich- 

 mond group, Boyle county, Kentucky. 



