30 PALEONTOLOGY OF NEW YORK. 



be regarded as a specimen of the latter species. The fragmentary specimen 

 represented on plate lxxv, fig. 1, is from a locality in Pennsylvania, and its 

 coalesced glabellar lobes indicate a distinct species. 



Distribution. Lower Helderberg group. Near Clarksville, Albany county; 

 Schoharie, Schoharie county. Oriskany sandstone: Township of Walpole, 

 Province of Ontario. Corn iferous limestone : Clarence Hollow, Erie county; 

 Lime Rock, Genesee county. 



Dalmanites (Hausmannia) concinnus. 



PLATE XI A, FIGS. 9-11. 

 Dalmanites concinnus. Hall. Illustrations of Devonian Fossils, pi. x, figs. 3-5. 1876. 



Pygidium only known. Outline sub-triangular, posteriorly acuminate. Surface 

 convex, trilobate. 



Axis relatively narrow, width less than one-third that of the shield, slightly 

 elevated along the axial line, and tapering to an abrupt termination within 

 the margin ; bearing nine to ten flattened transverse annotations, which are 

 thickened or faintly nodose on the axial line. 



Pleura broad, deflected in an even curve to the margins and bearing seven 

 or eight annulations which are broad, low and flat, and are separated by fine 

 narrow sulci. The first five annulations are grooved by fine impressed 

 lines, which extend to the margin. The anterior and posterior limbs thus 

 formed are of equal strength. The margin is slightly thickened, becoming 

 wider posteriorly and produced into a short and stout caudal spine. Surface 

 smooth or minutely granulose. 



Dimensions. The largest pygidium observed has a length of 16 mm., and 

 a width of 18 mm. ; the smallest a length of 9 mm., and a width of 10 mm. 



I H.stribution. Upper Helderberg group. Schoharie grit, Schoharie, Schoharie 

 county ; near Clarksville, Albany county ; Corniferous limestone, near Caledonia, 

 LivingstoD county; Cayuga, Province of Ontario. 



Dalmanites (Hausmannia) concinnus, var. serrula, n. var. 



PLATE XI A, FIG. 12. 



A single very small pygidium measuring 4 mm. in length and width bears 

 all the characters of the normal pygidium, but has in addition to them a row 



