29o 



between the lower and upper Marcellus shales in Central 

 New York. The present specimen measures a little over 

 an inch in irreatest diameter. 



AMMONOIDEA. 



Gexis BA(T1UTES. Saxdbekgeij. 



.[Ety. : Buktron, a staff.] 

 (1841: Leonli. iind Bronn's Jalirbuch, p. 240.) 



Shell long, straight, slender, gradually tapering, round or 

 elliptical in cross-section. The siphnncle is thin and near 

 the margin. The sutures have verv gentle lateral curves and 

 a funnel-shaped siphonal lobe. The protoconch is egg-shaped 

 and erect. 



Bactkites (iKAciEioK. Clarke. ( Fig. :22V). ) (LSDS: 

 Naples Fauna, p. 124, PL IN.) 



Distin^vishing- Character.^. — Section of ' "^ ^ 



uncompressed specimen sub-circular ; depth 

 of air chambers decreases rehitivelv from 

 the older to the newer parts: septa (piite 

 regularly concave, considerably oblicjue, 

 sloping toward the dorsum; fine, con- 

 centric, oblique, closely crowded snrface 

 lines on the young, and obscure, liroad, 

 and low oblique ribs on the adult shell, all 

 sloping backward to the (h^rsum ; fine 

 vertical sub-equal lines on the body cham- 

 ber, seen only on well-preserved specimens. 



T-i T • r j_i 1 1 j_ 1 Fig. 229. Buctrites 



b or discussion oi the development and graciuor. internal moid, 



I , . 1- i 1 • • /-11 1 . showing septa and si- 



relatioiis of this species, see ( la rkes mono- piionai lobe. enlarged 



'^ (after Clarke 1. 



graph, referred to. 



This species occurs in the black shale of the Styliolina 

 band, at Section 1 (replaced by iron pyrites). 



Bactkites aciculum. (Hall.) (Fig. 230.) {Coleohis 

 ackulum. Hall. Pal. N. Y., Yol. Y., Pt. H., p. 187, PL 

 XNNII.A.j 



