10 PALEONTOLOGY OF NEW YORK. 



original of D. acanlhopleiirus is from "near Schoharie, in limestone with Odonto- 

 cephalus (Onondaga limestone)." 



Distribution. Upper Helderberg group. In the Corniferous limestone, near 

 Clarksville, Albany county; Schoharie, Schoharie county; Canandaigua, 

 Ontario county; Lime Rock, near LeRoy, Genesee county. 



Dalmanites (Coronura?) emarginatus. 



PLATE XI A, FIGS. 7, 8. 

 atus, Hall. Illustrations of Devonian Fossils, pi. x, fig. 2. 1876. 



< >f this species fragments of the pygidia only, have been observed, which may be 

 characterized as follows; Outline sub-triangular, broadly emarginate behind; 

 apex of reentrant angle sub-acute. 



A :■/:. narrow, tapering evenly to an apex near the posterior border and con- 

 nected with the margin by a sharp, low ridge: it is composed of twenty 

 to twenty-two transverse annulations. 



Pleura broad, slightly produced upon the posterolateral areas, and bearing 

 seventeen to twenty broad and flattened annulations, which show a slight 

 tendency to duplicature toward the posterior extremity. The border is 

 narrow at the sides and widens a little posteriorly, where all the annulations 

 become obsolete upon approaching it. Surface ornamented by pustules, each 

 annulation bearing a single row upon the axis, and a double row upon the 

 pleurae. The axis hears five longitudinal rows, one in the axial line, and two 



'itherside. Upon the margin of the pygidium the pustules are more 



irregularly scattered. The lateral margins hear no spines and the posterior 

 border is covered only with granulations. 



The dimensions of the shield are approximately 22 mm. in length, and 32 



nun. in width. 



This little known species presents points of similarity with 



Dalmam ctans > bul differs in the following particulars, viz.: (a) the pos- 



gin is angulate and not transverse or crescentic, nor produced into 



