296 SYSTEMATIC PALEONTOLOGY 



equal on all parts of a whorl or they may be farther apart with interpola- 

 tions on the upper slope. The lunulae of the band are fine and regularly 

 curved." Ulrich, 1897. 



Occurrence. MARTINSBURG SHALE (Eden division). Jordans Knob, 

 one and one-half miles northeast of Fort Loudon; Tuscarora Mountain, 

 two and one-half miles southeast of McConnellsburg ; and Cowan Gap, five 

 miles northeast of McConnellsburg, Pennsylvania. Fragmentary casts 

 of this species were noted in the sandstone debris of the Upper Martins- 

 burg on the west slope of Eickard Mountain, Washington County, Mary- 

 land. 



Collection. U. S. National Museum. 



Genus LIOSPIRA Ulrich and Scofield 

 LlOSPIEA MICULA (Hall) 



Plate LVIII, Figs. 7-9; Plate LV, Figs. 25, 26 



Pleurotomaria micula Hall, 1862, Geol. Kept. Wisconsin, p. 55, fig. 1. 

 Liospira micula Ulrich and Scofield, 1897, Geol. Minnesota, vol. iii, pt. 2, 

 p. 994, pi. Ixviii, figs. 24-29. 



Description. Shell discoidal and small, rarely exceeding 16 mm. in 

 diameter and usually 11 or 12 mm., with the umbilicus filled by a reflexed 

 callosity of the inner lip. Externally this filling is concave, smooth and 

 distinct from the finely striated under side of the volutions. The shell 

 has four volutions with such shallow sutures that the spire forms an 

 almost even slope from its apex to the periphery. Surface marked with 

 fine lines of growth and in the best preserved specimens with very delicate 

 revolving lines. On the under side the lines of growth are broadly curved 

 with the greatest curvature on the inner half. The band is obliquely 

 placed on the periphery and most visible on the upper side. 



This is one of the long ranging gastropods, specimens apparently the 

 same as the types, which come from the Richmond (Maquoketa) of Wis- 

 consin, being found in all the formations from the Trenton to and 

 through the Eichmond. 



The usual specimens found are seldom well preserved and it is possible 

 that with better material differences may be noted in examples from the 

 various horizons. 



