CARBONIFEROUS PERIOD. 159 



Oedee pectinibeanciiiata. 



suboeder t^nioglossa. 

 Family NATICID^. 



Genus NATICOPSIS McCoy, 1844. 



Naticopsis nana Meek and Wortheu. 

 Plate XII, fig. 4 a and h. 

 Naticopsis nana Meek aud Wortbeu, 1866, Geol. Snrv. Illinois, ii, 365. 



Shell small, subglobose, wider than high ; spire much depressed ; volu- 

 tions about tln-ee, increasing very rapidly in size, last one large and ven- 

 tricose ; suture well defined ; aperture large, broad-subovate, somewhat 

 straightened at the inner side, its diameter nearly equal to seven-eighths of 

 the entire axial length of the shell ; outer lip thin ; inner lip not much 

 thickened ; columella slightly flattened. Surface marked by fine lines of 

 growth, which are a little stronger and more uniform on the upper side of 

 the whorls, near the suture, than elsewhere. 



Length, four millimeters; breadth, five millimeters. 



Our examples of this little shell agree so exactly with the description 

 and figures given by Meek and Worthen (Joe. cit.) that I have given the 

 foregoing description almost in the words of those authors. 



Position and locality. — Strata of the Carboniferous period; Camp Cotton- 

 wood, near Spring Mountain, Lincoln County, Nevada, where it was found 

 associated with Macrocheilus anguliferus White. 



Family CAPULIDJE. 



Genus PLATYCEEAS Conrad, 1840. 

 Platyceras Nebrascense Meek. 

 Plato XII, fig. 5 a, b, c, ami d. 

 Platyceras Webrasoensis Meek, 1872, II. S. Geol. Surv. Nebraska, 227. 



Shell small, elongate-conical, strongly curved or subspiral ; apex free, 

 bluntly pointed, more or less curved toward the body, and turned to the 

 dextral side of the shell; aperture irregularly oval; lip thin, broadly sinuous 



