436 Systematic Paleontology 



of the shell, especially the last one, which is also very ventricose in the 

 upper part, but rapidly contracted below, and produced anteriorly in a 

 more or less extended beak ; aperture elliptical in form, pointed at the 

 upper angle and prolonged below; columella strong, marked opposite the 

 middle of the aperture by three slender, almost thread-like oblique plica- 

 tions ; surface of the volutions, as shown by the casts, marked by strong, 

 rounded, vertical plications or folds, which become obsolete a little below 

 the swell of the volution and are also less distinct on the outer half of the 

 last one ; about eleven of the folds may be counted on the outer whorl." — 

 Whitfield, 1892. 



The axials number approximately eleven to each of the later volutions. 

 The shoulders of the whorls are finely lineated spirally, while the medial 

 and posterior portions are wound with low, broad fillets separated by 

 squarely channelled and somewhat narrower interspirals, about six in 

 number on the later whorls of the spire. 



The species has a very meager representation in the Monmouth of 

 Maryland. 



Occurrence. — Monmouth Formation. Brightseat, Prince George's 

 County. 



Collections.- — Maryland Geological Survey, Philadelphia Academy of 

 Natural Sciences, New Jersey Geological Survey. 



Outside Distribution. — Matawan Formation. Wenonah sand, New 

 Jersey. Monmouth Formation. Navesink marl, New Jersey. Selma For- 

 mation. Exogyra costata zone, Prairie Bluff, Alabama. 



Xancus intermedia (Weller) 



TurMnella intermedia Weller, 1907, Geol. Survey of New Jersey, Pai., vol. 

 iv, p. 767, pi. xc, figs. 18-22. 



Description. — " Internal casts short fusiform to subglobular in form, 

 with about three volutions, the dimensions of two nearly complete 

 examples being: Height 18 mm. and 13 mm., greatest diameter 17 mm. 

 and 11.8 mm. Apical angle about 75°, the spire about one-third the total 

 height of the shell, the volutions increasing somewhat rapidly in size, sub- 

 angular on the periphery and marked by rather strong vertical nodes, 

 which become obsolete before reaching the suture above, and also a short 



