INSTITUTE OF SCIENCE, PHILADELPHIA. 273 



twisted pillar and non-lirate throat ; outer lip thin, simple, arched forward; 

 inner lip slightly washed with callus ; last varix strong and prominent. Lon. 

 of shell 13,5 ; max. lat. 3.75 mm. 



This species differs from the preceding by its more rounded whorls, 

 fewer and much more prominent ribs, and slenderer spire; the last whorl also 

 is proportionately smaller. It was rather abundant in the marl. 



Bittium Cossmannii n. s. 

 Plate 21, figure 16. 



Older Miocene of the Chipola beds, Burns. 



Shell subconic, with two and a half smooth, rounded nuclear whorls and 

 six or seven rapidly increasing, inflated subsequent whorls ; varices numerous, 

 usually two or three on each of the larger whorls, with three small, periph- 

 eral, wavelike, transverse riblets between each pair of varices, or the riblets 

 may be obsolete; spiral sculpture of fine strise with wider interspaces, form- 

 ing fine, flatfish threads, with one wider flat thread just in front of the 

 periphery, and in advance of that one another on which the suture is wound ; 

 suture very distinct, deep, sub-appressed ; periphery nearer the anterior 

 suture; base spirally threaded, rounded; aperture wide, pillar very short 

 and feeble, canal short, wide; outer lip arched, slightly thickened, not Urate 

 within, a thin wash of callus on the inner lip. Lon. of shell ii.o; max. lat. 

 5.5 mm. 



This species recalls Mesostoma, but is obviously a Bittium. It is the 

 largest and most inflated species of the group. The body-whorl is remarka- 

 bly large and the varices numerous. It was found rather abundant, though 

 only one fully adult specimen was collected, from which the figure has been 

 drawn. It is respectfully dedicated to M. Cossmann, of Paris, France, whose 

 distinguished researches on the Parisian Eocene are well known. 



Bittium annettse n. s. 

 Plate 20, figure 3. 



Newer Miocene of the Cape Fear River, North Carolina, C. W. Johnson. 



Shell small, with two nearly smooth larval whorls and about seven sub- 

 sequent, sharply sculptured turns ; spiral sculpture of about six flattened 

 threads with narrower interspaces on the base, behind that on the last whorl 

 five sharply elevated threads with wider interspaces; on the preceding whorls 

 three of these persist, sometimes showing the others faintly, intercalated; 

 these are crossed, except on the base, by sharp riblets of about equal size, 

 equally spaced, and somewhat nodulous at the intersections ; the lines of 

 growth are quite distinct. The transverse ribbing stops short of the sutures, 

 which consequently have a channelled appearance, though really closely 

 appressed ; there is a single obscure, swollen varix behind the outer lip 

 about one-third of a turn ; base rounded, aperture subovate ; outer lip thin, 



