294 Systematic Paleoxtology — Middle Devoxiax 



Descnpiioit. — " Shell very ventiieose; spire short, consisting of four or 

 five volutions, the last one extremely ventricose, making nearly two- 

 thirds the entire height of the shell; aperture longitudinally oval, obtuse 

 below. Surface distinctly striated by iine lines of growth; suture-line 

 deeply impressed."' Hall, 1879. 



The Maryland specimens arc all internal impressions which are almost 

 if not quite smooth. The size and form of the shell, number of volutions, 

 the ventricose bodj^-whorl which is about two-thirds the entire length of 

 the shell (in one specimen the shell is 21 mm. in length and the body- 

 whorl 14 mm.), and the deep suture-lines noted on the Maryland speci- 

 mens are, however, quite distinctive characters of this species. Toward 

 the aperture of several specimens are indications of somewhat strong folds, 

 probably of growth and perhaps striae are faintly shown crossing the 

 body-whorl in the same direction as the folds. 



Hall figured the opposite sides of an internal impression from the 

 Hamilton at Cumberland, Md.. which he called this species (Pal. X. Y., 

 vol. V, pt. ii, pi. xii, figs. 10, 11) and many of these specimens agree 

 almost exactly with these two figures. The internal impressions are 

 somewhat similar to those of Pleurotomaria itijs Hall but do not show 

 any indication of the spiral band which characterizes the internal impres- 

 sions of that species. 



Length, 31-23 mm.; width, 18-19 mm. 



Occurrence. — Romney Formation, Hamilton Member. Western 

 Maryland. 



Collections. — Maryland Geological Survey; American Museum of Nat- 

 ural History. 



Genus LOXONEMA Phillips 



Loxoxe:ma itajiiltoxiae Hall 



Plate XXXVI, Figs. 16-19 



Loxonenia nexilis Hall, 1843, Geol. N. Y., pt. iv, p. 201 (not Phillips). 

 Loxonema hamiltoniae Hall, 1861, Descriptions of New Species of Fossils, 

 etc., p. 25. 



