306 SYSTEMATIC PALEONTOLOGY 



at several localities in the vicinity of Hagerstown, Maryland. Natural 

 sections of this shell can be seen in the lower Stonehenge quarries and 

 especially in the fences along the National Highway, one-fourth to one- 

 half mile south of Funkstown, Maryland. 



Not uncommon in the Tribes Hill formation of the Canadian near 

 Fort Hunter, New York. 



Collection. U. S. National Museum. 



ECCYLIOMPHALUS TRENTONENSIS (Conrad) 



Plate L, Figs. 19, 20 



Cyrtolites trentonensis Conrad, 1842, Jour. Acad. Nat. Sci., Philadelphia, 



vol. viii, p. 270, pi. xvii, fig. 4. 

 Cyrtolites trentonensis Hall, 1847, Pal. New York, vol. i, p. 189, pi. xla, 



figs. 3a-d. 

 Eccyliomphalus trentonensis Weller, 1903, Geol. Surv. New Jersey, Pal., 



vol. iii, p. 184, pi. xii, figs. 20, 21. 



Description. Shell consisting of less than one volution, increasing 

 gradually in size from the apex, coiled in one plane. Cross-section 

 angularly subovate. Ventral side of the shell convex from the periphery 

 to the inner margin; the periphery rather sharply rounded; about mid- 

 way between it and the inner margin, on the dorsal side of the shell, is an 

 angular, subcarinate ridge, the space between this ridge and the peripheral 

 angulation being nearly flat; from the dorsal ridge to the inner margin 

 of the shell the surface is convex. The surface is marked by rather 

 obscure and irregular lines of growth, which, on the dorsal side, slope 

 backward to the dorsal ridge, thus indicating the presence of an angular 

 sinus in the aperture at that point. The most complete specimen observed 

 has a length of about 35 mm. around the periphery of the shell from apex 

 to aperture." Weller, 1903. 



Occurrence. MARTINSBURG SHALE (Sinuites bed). Carlisle, Cham- 

 bersburg and two miles south of St. Thomas, Pennsylvania. The Lower 

 Trenton rocks of New York and New Jersey likewise have furnished 

 specimens. 



Collection. U. S. National Museum. 



