GASTROPODA. 871 
Protowarthia planodorsata. | 
Formation and locality.x—At present this species is known certainly only from the Utica group in 
the vicinity of Cincinnati, Ohio. 
Collection.—E. O. Ulrich. 
PROTOWARTHIA PLANODORSATA, 7. sp. (Ulrich.) 
PLATE LXIII, FIGS. 31—35. 
Of this form we have six specimens. These show that it is of the type of P. 
granistriata,—perhaps it should be called a variety of that species,—differing in 
having the flattening of the back of the last volution much more decided, while the 
central ridge is wanting entirely, at any rate it is so for the outer volution. The 
dorsum of the volutions seems to be rather narrowly rounded. The surface 
markings are essentially the same in the two forms, as is also the form of the 
aperture and the dimensions, the largest specimen being about 24 mm. in hight. 
The broad dorsal flattening will distinguish P. planodorsata at once from all 
other species of the genus and family known. 
Formation and locality.—Utica group, Covington, Kentucky. 
Collection.—H. O. Ulrich. 
PROTOWARTHIA PERVOLUTA, %. Sp. 
PLATE LXIII, FIGS. 21—27. 
This also may be only a variety of P. granistriata, but it is one well worthy of a 
distinct name. It is almost constantly smalltr, the hight in the majority of the 
specimens being less than 15 mm., and in only one out of over fifty is it 20 mm. 
Comparing the two forms we find that P. pervoluta is more closely inrolled, giving a 
ore globose form. The aperture also is relatively wider and the umbilical callosity 
has a columella-like twist that is not seen in P. granistriata. The volutions further 
are nearly uniformly rounded dorsally and never show anything either of a central 
ridge or a flattening. Though some of the specimens before us are tolerably well 
preserved, none of them exhibit any satisfactory evidences of external markings 
save the granostriate marking of the inner volution. This is more extensive, but in 
other respects essentially as in the two preceding species. Here and there a small 
patch of the external layer is retained and these sometimes exhibit faint traces of 
exceedingly delicate transverse and revolving lines. 
Formation and Iccality.—In Kentucky this species occursin the Black River group and in the lowest 
bed (Orthis or Modiolodon bed) of the Trenton group. In Minnesota casts of the interior are not uncom- 
mon in the Rhinidictya and Ctenodonta beds of the Black River group at St. Paul and Minneapolis. 
Testiterous examples are rare here, but further south near Cannon Falls and at Chatfield they are more 
abundant. : 
Collections.—H. O. Ulrich; W. H. Scofield. 
