PALAEONTOLOGY OF NEW YORK. 

 Dalmanites (Chasmops) macrops. 



PL \TK XI 1!, FIGS. II. 15. 



lania mcKrops, Hall. Descr. New Species of Fossils, etc., p. 59. 1861. 



nacrops, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 87. 1862. 

 — , — -. Illustration of Devonian Fossils, pi. xiii, figs. 9, 10. 1876. 

 (Not mentioned in the explanation of t lie plate). 



A portion of the Cephalon is the only part of this .species known. It is lunate 

 in outline, border narrow and thin. 



Glabella long, equaling four-fifths the length of the shield Frontal lobe 

 sub-rhomboidal, one-third wider than long ; first pair of lateral furrows long, 

 inclined backward and nearly meeting ; second lateral furrows obsolete except 

 at their proximal extremities; third lateral furrows inconspicuous, inclined 

 a little forward. The first and second glabellar lobes are coalesced and some- 

 what more elevated than the highest point of the frontal lobe. The third 

 pair of lobes is inconspicuous and transverse. Occipital furrow narrow and 

 shallow ; occipital ring broad, rounded and strongly arched. 



Eyes very large, elevated above any other portion of the cephalon. 

 Visual surface measuring 9 mm. in height, and bearing about 500 lenses. 

 Palpebrum scarcely prominent ; palpebral lobe relatively small and closely 

 appressed to the compound middle lobe of the glabella. Orbital sulcus 

 distinct. 



The Cheeks appear to have been relatively small and depressed or flattened 

 near the margin. 



Surface finely pustulose upon the glabella, smooth or granulose upon the 

 cheeks and occipital ring. 



The single specimen by which this species is represented has a length of 

 20 mm., and a width of 38 mm., and presents about the characters which, 

 from comparison with the species Dalmanites Calypso, might be expected in 

 the cephalon of I). Erina. Whether the latter species, which is now known 

 only from its pygidia, should be united with D. macrops must be left io a 

 more complete knowledge of these fossils. 



Distribution. Upper Helderberg group. Corniferous limestone: Schoharie. 



