62 PALAEONTOLOGY OF NEW YORK. 



Dalmanites (Chasmops) anchiops, var. abmatus. 



PL \TK IX, FIGS. 7-9. 



Pita, .11 m.i,. Foster and Whitney's Geol. Rept. Lake Superior, p. 124. 1S51. 



kiops, var. armata, Hall. Descr. New Species of Fossils, etc., p. 56. 1861. 



Da i, var. armata, Hall. Fil't th Rept. N. Y. Stati> Cab. Nat. Hist., p. 84. 1S62. 



Dili: . hiops, var armata, II ILL. Illustrations of Devonian Fossils, pi. ix, figs. 2, 7, S. 1S76. 



The points of variation iii these specimens may be thus summarized: (a) the 

 spine upon the occipital ring is very long, round and very stout toward the 

 base. Its length is sometimes quite equal to the length of the glabella, while 

 in the typical forms of the species the spine is not more than one-third or 

 one-fourth of that length; (b) the genal spines are inconspicuous or obsolete; 

 (c) the surface, as shown in casts of the exterior, is free from tubercles or 

 other ornamentation; (d) the eyes appear to be less elevated and bear fewer 

 corneal lenses. 



As the cephala of this character have not been found in conjunction with 

 the other parts of the animal, it is impossible to determine whether the thoraces 

 and pygidia belonging thereto, also varied from the type, since none of these 

 parts have been seen which show any variation from the normal form. The 

 largest cephalon observed has a length of 80 mm., and a width of 116 mm., 

 indicating an animal upwards of '2(H) mm. in length when entire. 



Dalmanites anchiops, var. sobrinus, n. var. 



PLATE IX, FIG. 11. 

 Dalmanites, n. sp. ? Hall. Illustrations of Devonian Fossils, pi. ix, fig. 11. 1876. 



A single cephalon from the Schoharie grit has the general proportions of the 

 speeies, |, u t shows a variation from the foregoing in the following particulars, 

 viz.: (a) the glabella is much more convex, and projects slightly beyond the 

 frontal margin, (b) the genal angles appear to be without spines, (c) the 

 occipital ring bears no spine, (d) the facial suture, where it crosses the sum- 

 mit of the cheek, lies in a much deeper sulcus. The original is a cast of the 

 lower surface and is somewhat imperfect, but its features seem to be dis- 

 tinctly varietal. 



