246 
PALAEONTOLOGY OF NEW-YORIt. 
Fig. 2 a. An entire specimen, preserving the posterior spines of the buckler. 
Fig. 2 b. Front view of the same, showing the elevation of the oculiferous tubercles. 
Fig. 2 c. A small specimen with the surface markings obscure. 
Fig. 2 d. Lateral view of a specimen, showing the extension of the extremities of the lateral articulations. 
Fig. 2 e. Caudal shield of a larger individual. 
Fig. 2 f. An enlarged portion of the buckler of 2 «, showing pustulose tubercles, which appear much 
like the tubercles on the surface of Echinus or Cidaris, for the attachment of the spines. 
The oculiferous tubercle, under an ordinary magnifying glass, presents only small un¬ 
arranged granulations. 
Fig. 2 g. The caudal shield and a portion of the thorax enlarged, showing the tubercles upon alternate 
and third segments. 
Fig. 2 h. Profile of the same. 
Position and locality. This rare species occurs in the lower shaly portions of the Trenton 
limestone, being scarcely known except in the soft argillaceous beds, which admit of 
their nearly perfect preservation. I am indebted to Mr. Wadleigh, of Middleville, for 
several very good specimens. (State Collection.) 
303. 4. CERAURUS? PUSTULOSUS. 
Pl. LXI. Figs. 2 a, b. 
The specimen is a fragment, apparently of the lower side of the maxillary shield, with 
the prolonged posterior extremity. It is clearly distinguishable from the preceding species, 
by the large pustulose markings with a finely granulated surface between. 
It is not easy to decide positively regarding this fragment, and further discoveries may 
prove it to belong to the Genus Acidaspis , which in its surface marking is allied to Ceraurus. 
The margin presents some elevated tubercles or fine lines which are not represented in the 
figure. 
Fig. 2 a. The fragment, natural size. 2 b. A magnified portion of the same. 
Position and locality. This fragment was obtained from the higher beds of the Black- 
river limestone, near its junction with the Trenton limestone, at Watertown. 
(From Dr. Crave.) 
very similar to the one under consideration, and the difference of geological position renders it desirable to point out 
any differences of character. In the Dudley specimens, though not larger than ours, there are at least twenty-five 
segments in the middle lobe and eight or nine in the lateral lobe, every fourth articulation is tuberculated, and the 
tuberculations on the lateral lobes are nearer the axial lobe. The surface, also, appears not to have been as roughly 
granulated as in the Trenton species. Hisinger cites Calymene punctata as from the more recent Transition 
limestone, and Murchison has given it from the Caradoc sandstone. There are doubtless two species referred to this 
name, and I have regarded the one under consideration as differing from the species of Wahlenberg, Dalman, 
&c., though closely allied to it. 
