258 POTTSVILLE FAUNA OF OHIO 



ure. They are preserved as internal casts to which small portions of 

 the shell still adhere. The body whorl appears to be much less flattened 

 above than is indicated by Meek's figures. 



Horizon and locality. McArthur limestone: Vinton County, 

 Moore mine, Locality 84, r. 



Naticopsis ventricosus (Norwood and Pratten) 



1855 Natica ventricosa. Norwood and Pratten, Jour. Acad. Nat. Sci. Phil., 2nd Ser., 

 Vol. 3, p. 76, PI. 9, Figs. lOa, b. 

 Coal Measures: one mile south of New Harmony, Indiana. 



Remarks. A single, fairly well preserved specimen from the 

 Lower Mercer limestone of Muskingum County has the form and 

 surface markings of Meek and Worthen's figure ISa, 1 a form which 

 these writers believed to be the same as that which Norwood and Pratten 

 designated as Natica ventrica in spite of somewhat marked differences, 

 real or supposed, which apparently existed. The characters of the 

 aperture are not shown on the specimen examined. 



Dimensions. Height of shell 14 mm., height of body whorl 11 mm., 

 maximum width 13 mm. The specimen examined is slightly distorted 

 by pressure. 



Horizon and locality. Lower Mercer limestone: Muskingum 

 County, Symmes Creek, Locality 29, r. 



Genus Trachydomia Meek and Worthen 

 Trachydomia sp. 



Remarks. Two crushed specimens of a gastropod from the 

 Lower Mercer and Black Flint members have been referred to the 

 genus Trachydomia, but due to the imperfect condition of the shell no 

 specific determination is possible. The aperture and the lip are 

 obscured. However, in its specific relationship it seems most closely 

 related to T. noduloda in size and in number and character of surface 

 nodes. 



Horizon and locality. Lower Mercer limestone : Muskingum 

 County, Locality 38, r. Black Flint member: Vinton County, Lo- 

 cality 92, r. 



Genus Zygopleura Koken 



Zygopleura plenum (Herrick)? 

 PI. XVI, figs. 1, 2 



1887 Loxonema sp. Herrick, Bull. Den. Univ., Vol. 2, p. 22, PI. 3, Fig. 2. (The specific 

 name L. plenum is suggested on p. 147.) 

 Coal Measures: Flint Ridge. 



Meek and Worthen, Geol. Surv. 111., Vol. 5, p. 592, PI. 28, Fig. 13a, 1873. 



