The TSarly Stages of Bin-trite*. — Clarke. 39 
points of agreement in his specimens with the diagnostic 
characters of Bactrites. Though not venturing to determine 
their specific characters, he felt that the evident marginal 
position of the sipho was sufficient to establish their generic 
relations. Against this interpretation the writer can urge 
nothing, but only set forth the character of the material 
which has passed under his own observation. 
Bactrites, as defined by its founder, G. Sandberger (1N41 ). 
is based upon the species B. gracilis G. Sandb.. the original 
localities of which are Wissenbach and Budeshehn. The 
shells of the genus are long, slender, slowly expanding tubes 
having an elliptical cross section, gently oblique septa, some- 
what expanded aperture and the* surface covered with fine 
concentric lines, which are more or less oblique and make a 
slight retral bend above the position of the sipho. As speci- 
mens are usually preserved, the sipho appears to be distinctly 
marginal. Upon internal casts of the shell the sipho seems 
almost invariably to make a distinct lobe in the margin of 
the septum. The structure at this point, however, is delicate, 
and such casts may readily convey an inexact conception. 
The position of the sipho is not precisely marginal, but a very 
narrow moiety of the septum lies between the tubular siphonal 
collar or funnel and the wall of the shell. A very slight varia- 
tion in the direction of this collar, which is often perfectly ap- 
parent in any single specimen, will, in case of an outward in- 
clination, attach the collar to the shell-wall, but if the direc- 
tion be inward the collar may remain altogether free from the 
shell. This structure is seen in the accompanying figure 
(Plate II, fig. 3). The detachment of the shell-wall usually, 
indeed almost invariably, carries with it the outer portion of 
the collar, thus forming very distinctly an apparent dorsal lobe. 
It is the presence of this lobe that Branco has taken as giving 
the generic status to his specimens. 
The material upon which the observations here made are 
based has been derived from the Naples beds or the horizon 
of the Goniatitcs intumescens fauna, in various localities in 
Ontario and Livingston counties, New York. Its representa- 
tion is abundant and its preservation exceptionally favorable. 
A few of the specimens are preserved in pyrite, some arc 
in limestone and shale, but the great majority are exquisitely 
