224 NEW YORK STATE MUSEUM 



Dalmanites limulurus (Green) (Fig. 155). Phacops limu- 

 lurus Hall (1852. Pal. N. Y. 2:303, pi. 67) 



Distinguishing characters. Sublunate form of cephalon, pointed 

 anteriorly; large slender genal spines; broad anterior and narrow 

 posterior lobes of glabella; pygidium with 15 axial rings, and a long, 

 strong mucronate spine. 



Found rarely in the lower and middle but abundantly in the upper 



Rochester shales at Niagara. Also at Lockport and elsewhere 



(Hall).. 



Genus calymmene Brongt. 



[Ety. : ■/.z-/.aXuiJ.[jA'M)<$^ concealed] 



(1822. Hist. nat. cor list. foss. p. 7) 



Body oval in outline, readily enrolled; cephalon wider than long; 



glabella narrowing anteriorly, conic, strongly convex, divided by 



three pairs of deep glabellar furrows. Facial sutures extending 



from just in front of the genal angles, converging forward around 



the eyes and reaching the anterior margin separately. Eyes small; 



thorax of 13 segments, with deep axial furrows; 



pygidium from six to 11 segments not distinctly 



marked ofif from the thorax. 

 i 



Calymmene blumenbachi niagarensis Hali (Fig. 



156) (1852. Pal. N. Y. 2:307, pi. Gy) 

 Distinguishing characters. Semicircular out- 

 \ , line of cephalon; glabellar lobes tuberculiform ; 



general tapering form of thorax; axis of pygi- 

 dium with about eight rings ; limb grooved nearly 



Fig. 156 Calymmene 



blumenbachi niagarensis ^^ margin, which is thickcncd and rounded 

 posteriorly. 



Found rarely in the Clinton limestone lenses, and the lower 

 Rochester shale at Niagara. Also at Lockport (Hall). 



Genus lichas Dalman 



[Ety.: mythologic name] 



(1826. Ueber die Palaeaden, p. 71) 



Trilobites with large and flat granulated shell. Cephalon small, 

 with spinous genal angles; glabella broad, with a large, tumid an- 

 terior lobe, which dominates the smaller reniform lateral lobes on 

 ■each side; eyes small; facial suture extending from the posterior 



