85 



Another figure is given by thefe authors deflitute of ribs, 

 and of the crenated margin, fhewing the internal flrudlure 

 of the concamerations ; tlie fyphon of each feptum is pro- 

 duced the lame ns the external one. 



A mod elegant fliell of this kind is found fodil upon the 

 Appejiines, near Sienna, feveral of wliich we have been fa- 

 voured with by Mr. Mead, and Mr. Higginson. Thefe 

 vary a little, but the moft jjerfecl are an inch in length, 

 completely cylindric except at the lafl joint, which is rather 

 larger, and terminates conically, ending in a fmall protube- 

 rance, nearly half as long as the joint to which it belongs : 

 the anterior end of thofe whicli appear perfecSl, is a little 

 contra6ted, round, and fmooth, or proje<5lirig beyond the 

 ribs ; in the centre is placed the aperture, or fyphon, whofe 

 margin is finely crenated. They vary alfo as nmch in the 

 number of chambers, as in that of the ribs ; pofTefling from 

 ten to fifteen of the former, and from nine to twelve of the 

 latter : the joints are not mucli raised, hut ulually two or 

 three at the anterior end more than the reft. The (hell is 

 extremely thick in jjroportion ; and we found by dividing 

 feveral down the middle, that the fepta were equally firong, 

 and each furnifhed with a fmall crenated perforation in the 

 middle, but not a continued fyphon : the cells are not round, 

 but in the fe(5iion appear rather concavo-convex, The co- 

 lour is of a pearly-white. 



May not this be a variety of tlie JV. cojlatus of fuperior 

 growth, occafioned by a more fouthern climate .'' but whether 



it 



