12 
PALEONTOLOGY OF NEW YORK. 
BRONTEID^. 
BRONTEUS, Goldfuss. 1843. 
Bronteus Tullius, n. sp. 
PRATE VTII A, FIGS. 34-36. 
Cephalon and Thorax unknown. 
Pygidium flabellate, comparatively small; outline semi-ovate, anterior margin 
rounded and incurved toward the axis. Length to width as 2 to 3. 
Surface depressed, gently elevated and convex about the axis, becoming 
concave toward the margin and slightly retlexed at the edge. 
Axis short, about one-fourth the length of the shield; width about twice 
the length. Outline broadly trigonal. Articulating ring prominent, but not 
well preserved in the type specimen. No annulations visible. 
Pleura, very broad and bearing fifteen broadly flattened and simple annula¬ 
tions. Of these the widest lies in the axial line with seven on either side. 
These annulations are nearly straight, radiating evenly from the margins of 
the axis and separated by narrow, sharply impressed sulci. Both the annula¬ 
tions and sulci become obsolete before reaching the border, the posterior 
ones not extending so far as the anterior. The border is ornamented with a 
single row of minnte spinules, numbering about twenty-five along the termi¬ 
nal margin of each annulation; these measure scarcely 1 mm. in length and 
are inclined slightly upward. Doublure very broad, extending fully half way 
across the pygidium. 
Test extremely thin; the portions retained are strongly and regularly 
pustulose, the pustules on the ribs apparently extending to the margin. The 
doublure is marked by distant, sub-parallel, anastomosing, lamellose lines. 
The type specimen has a length of 15 mm. and a width of 21 mm. 
Another specimen of limestone from a different locality bears the epis- 
tomal doublure of some trilobite. This fragment is broadly convex and 
prominent over the central area and constricted toward the sides, and is quite 
unlike the frontal doublure of any associated species of crustacean, but has 
