166 PROCEEDINGS OF THE ACADEMY OF [1890. 



variable and are dependent largely upon the accidental station of 

 the mollnsk. The type specimen is imbedded in a hard matrix — 

 only the interior of the shell being exposed to view. Meek's figures 

 were made from plaster casts of the interior, so that no surface mark- 

 ings are discernible. 



Capulus paralius (AVhite & Whitfield). [Plate IT, figs, la, lb.] 



Platyceras paralmvi White & Whitfield, 186'2. Proc. Boston Soc. Nat. His- 

 tory, vol. V'lII, p. 303. 



Platyceras paralium Keyes, 1889. Proc. Acad. Nat. Sci., Phila., 1889, p. 294. 



Capulus paralius Keyes, 1890. Am. Geol., vol. V. 



Shell small, forming about two rapidly expanding volutions, which 

 are not contiguous ; apical portions minute, slender, laterally com- 

 pressed, subangular along the dorsum, more or less distinctly plicate. 

 Aperture irregularly pentagonal ; labrum sharp, deeply sinuous, or 

 somewhat serrate. Surface marked by few subimbricate lines of 

 growth. 



Horizon and localities. Kinderhook beds : Des Moines and iVIar- 

 shall counties, Iowa ; Lodi, Ohio. 



The apical portion of the shell is more slender and extended than 

 the type would indicate from a casual examination. The smaller 

 specimen figured (Plate II, fig. lb) shows the spire perfectly pre- 

 served. The type (Plate II, fig. la) has the longitudinal folds 

 much more prominent than is apparent in a representative specimen 

 of the species. In some examples the plications are hardly notice- 

 able. This species is widely distributed geographically, ranging 

 froniLe Grand, in central Iowa, to the southeastern part of the State 

 and thence to Ohio. 



Capulus subplicatus (Meek & Worthen). 



Platyceras [Orihonyc/iia) subplicatum Meek & Worthen, 1866. Proc. Acad. 

 Nat. Sci. Phila. 1866, p. 265. 



Platyceras {Ortkonychia) subplicatum Meek & Worthen, 1868. Geol. Sur. 

 Illinois, vol. Ill, p. 457, pi. XIV, figs. 4a, 4b, 4c. 



Shell small, depressed, obliquely conical ; anterior slope somewhat 

 convex ; posterior and lateral slopes slightly concave or straight ; 

 several large broad undefined plications extend from the apertural 

 margin nearly two-thirds the distance to the aj^ex. Aperture sub- 

 circular. 



Horizon and locality. Kinderhook beds : Richfield, Ohio. 



This species is known only from natural casts. The specimens 

 exhibit well the muscular scars which are described as " obliquely 

 elongated, subovate or sublunate, and vertically striated, placed a 



