No. 4.] DANA — ON THE TACONIC. 479 



Stenuthfx'a pauper, spec. nov. 



Deseription. — Shell small, conical, with the apex incurved, 

 laterally compressed. Aperture ovate, elongated in the plane in 

 which the curvature of the apex occurs. Surface with four or 

 five small engirdling convex ridges. Length of aperture about 

 H lines; width about 1 line; height of shell about 1 line. 



Occurs in the red limestone at Bridgus, Conception Bay. 



In the Quar. Jour. Geol. Soc. of May last, Mr. Hicks has de- 

 scribed and figured, under the name of Stenotlieca cornucopia^ a 

 small shell which is evidently congeneric with this. To the same 

 genus should perhaps be referred the shell known as Metoptoma 

 rugosa of the Lower Potsdam ? of New York. 



ScENELLA Reticulata, gen. and spec. nov. 



Description, — Shell small, almost uniformly depressed, conical ; 

 apex central or nearly so ; an obscure carina extending from the 

 apex down one side to the margin. Aperture nearly circular, 

 apex very slightly incurved towards the side opposite the carina. 

 Surface reticulated with fine radiating and engirdling striae, just 

 visible to the naked eye. Diameter of the aperture of the largest 

 specimen collected, 3 lines ; height of the apex, 2 lines. 



Occurs at Topsail Head, Conception Bay. 



Species resembling this have been heretofore referred to Capu- 

 h(s, Metoptoma ^ &c., to which, however, they do not belong. For 

 the present I propose to refer those with a strongly corrugated 

 surface to Stenotheca, and the others with a smoother surface to 

 SceneUa. 



(^To he Continued.^ 



\YHAT IS TRUE TACONIC ? 



By Prop. James D. Dana. 



The true use of the term Taconic should be learned from Prof. 

 Emmons's first application of it when he made his formal an- 

 nouncement of the " Taconic system." In his final New York 

 Geological Report, 4to., 1842, the rocks so-called are those of the 

 Taconic mountains, on the borders of Massachusetts and New 

 York, together with the quartzite, limestone, and slates adjoining 

 on the east,* and not the slates far west of these mountains ; f 



♦ Professor Emmons opens the subject of the " Taconic System " 

 in his final Report (1842) by saying that it extends north through 

 Vermont to Quebec, and south into Connecticut ; but the only rocks 

 he describes as the rocks of the system are those of Berkshire County, 



