Maryland Geological Survey ' 227 



defined, rounded, direct, extending to the post basal extremity. Surface 

 marked by very fine concentric striae, and by irregular varices of growth, 

 which sometimes produce strong undulations in the surface of the shell." 

 Hall, 1885. 



This is one of the most abundant species of Nucula found in Mary- 

 land and most of the variations represented by the figures of the New 

 York specimens occur. The larger specimens from the arenaceous shales 

 of Evitts Creek below Wolfe Mill are somewhat flattened and show promi- 

 nent varices of growth between which are the fine concentric striae; while 

 specimens from the West Virginia side of the Potomac River three miles 

 below Cumberland are rather smaller, not compressed and quite gibbous 

 in the umbonal region. This species is readily identified from the posi- 

 tion of the beaks, its subequilateral triangular form, fine concentric striae 

 and irregular varices. 



Length, 10-19 mm. ; height, 8|-15 mm. 



Occurrence. — Romney Formation, Hamilton Member. B. & 0. R. R. 

 cut at 21st Bridge; W. Va. Cent. R. R. cut at 21st Bridge. Williams 

 Road, 31,4 miles southeast of Cumberland; east bank Evitts Creek below 

 Wolfe Mill ; in Jennings Run % mile west of Corriganville ; on east side 

 Warrior Mt. east of Rush ; on Oldtown Road east of Maryland Ave., Cum- 

 berland; McCoys Terry; southwest of McCoys Ferry; on Hancock-Har- 

 risonville Road aboixt 2 miles north of Hancock; Ernstville; W. Va. side 

 Potomac River 3 and 4 miles south of Cumberland ; on Romney-Hanging 

 Rock Road about 1/. mile north of Romney, W. Va. ( ?) ; hill 3 miles south 

 of Cumberland. 



Collections. — ]\Iaryland Geological Survey; New York State Museum; 

 American Museum of Natural History. 



NucriLA BELi.iSTRiATA (Conrad) 

 Plate XXV, Figs. 1-5 



Nuculites bellastriata Conrad, 1841, GeoL Surv. N. Y., An. Rep., p. 40. 

 Nucula bellastriata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 2. 

 Nucula bellistriata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, 

 p. 318, pi. xlvi, figs. 1-9. 



