448 Systematic Paleontology 



Occurrence. — Matawan Formation. ? Arnold Point, Severn River, 

 Anne Arundel County. Monmouth Formation. Brightseat, Prince 

 George's County. 



Collections. — Maryland Geological Survey, Philadelphia Academy of 

 Natural Sciences, New Jersey Geological Survey. 



Outside Distribution. — Matawan Formation. Marshalltown clay marl, 

 New Jersey. Monmouth Formation. Navesink marl, Tinton beds. New 

 Jersey. 



Pyropsis reileyi Whitfield 



Pyropsis reileyi Whitfield, 1892, Mon. U. S. Geol. Survey, vol. xviii, p. 42, 



pi. ii, fig. 17. 

 Pyropsis trochiformis Weller, 1907, Geol. Survey of New Jersey, Pal., vol. 



iv, p. 746, pi. lxxxvii, figs. 1-3 (ex parte). 



Description. — " Shell of medium size, subglobular or globularly ovate 

 in general form, with a moderately elevated spire and subventricose volu- 

 tions, which are somewhat rapidly enlarged outwardly; volutions about 

 three in number, the last one forming the principal bulk of the shell, and 

 regularly rounded from the suture line to the beginning of the very slightly 

 extended anterior beak; the inner volutions nearly on a level with each 

 other, but the outer one dropping more rapidly below the inner, giving 

 the greater height to the spire ; volutions regularly rounded, without any 

 angulation in the upper part, especially on the last one; aperture large, 

 semi-lunate, modified above on the inside by the projection of the inner 

 volution ; cavity left in the cast by the removal of the columellar axis very 

 large and marked on the surface by a series of circular protuberances 

 which gradually increase in size with the growth of the shell; the inner 

 one of four, which can be seen on one cast, and which is situated at the 

 inner limit of the last volution, is only about one-twelfth of an inch in 

 diameter, while the outer one is rather more than one-fourth of an inch 

 across ; the surface of the shell marked by several strong, coarse, revolving 

 ridges, which have left their imprint only very slightly on the surface of 

 the cast; the outer lip of the shell seems also to have been slightly 

 expanded, at least near the upper part of the aperture. 



