Maryland Geological Survey 295 



Loxonema hamiltoniae Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., 



p. 53, pi. iv. fig. 8. 

 Loxonema hamiltoniae Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 45, pL xiii, 



figs. 15, 17. 

 Loxonema namiltoniae Clarke, 1903, N. Y. State Mus., Bull. 65, p. 539. 

 Loxonema hamiltoniae Grabau and Shinier, 1909, N. Am. Index Fossils, vol. 



1, p. 693, fig. 989. 



Description. — " Shell elongate; volutions moderately convex, about thir- 

 teen in the largest specimens, very gradually increasing in size from the 

 minute apex, the last one ventricose; aperture ovate, narrowing below; 

 columella extended. Surface marked by longitudinal sharp, curving 

 striae, which bend gently backward from the suture, and forward towards 

 the base of the volution, having the greatest curve near the middle, those 

 of the last volution curving abruptlv backward to the columellar lip ; 

 striae separated by distinctly defined grooves which are a little wider than 

 tlio ridges; the striae increasing in distance as the shell grows older." 

 Hall, 1S79. 



A specimen in the Maryland Collection shows clearly five whorls and 

 the impression of two additional ones. The volutions are fairly convex, 

 crossed by rather coarse, sharp curving longitudinal striae, which are 

 separated by grooves somewhat wider than the ridges. At the sutures 

 there is no banding of the upper edge of the volution as in the closely 

 related species of L. delpliicola Hall, the absence of which together with 

 the agreement of the other characters with those of L. hamiltoniae is 

 regarded as proving the correctness of the identification of this specimen 

 as L. hamiltoniae. All the type specimens of L. delpliicola Hall in the 

 office of the New York State Paleontologist show a prominent sutural 

 band. 



Length of the last five volutions, 17 mm.; width of last volution, about 

 S ram. 



Occurrence. — Eomney Formation, Onondaga Member. Williams 

 Koad, 31/2 miles southeast of Cumberland. Hamilton Member. 4^/4 

 miles northeast of Oldtown; east bank Evitts Creek below Wolfe Mill; on 

 road about half way between Eomney and Hanging Eock, W. Ya. ; on road 

 1 mile north of Eomney, W. Ya. ( ?) . 



