108 PALEONTOLOGY OF NEW YORK. 



The doublure is strongly rounded and incurved, somewhat excavate at the 

 geual angles, sharply convex and ridged upon the genal spines. Its surface is 

 marked by longitudinally parallel, lamellose lines. 



Distribution. Upper Helderberg group. Corniferous limestone: Columbus, 

 Ohio; Falls of the Ohio, Ky. 



Proktus Verneuili. 



I'l, \ I K XX, I IGS. is, l». 



Proitus VerTieuili, Hall. Descr. New Species of Fossils, etc , p. 73. 1861. 



; ; ;. Hall Fifteenth Rept. N. V State Cab. Nat. Hist., p. 101. 1862. 

 '!.< Verneuili, Hall. Illustrations of Devonian Fossils, pi xx, figs. 18, 19. 1S76. 



The cephalon and thorax of this species have been observed only in a con- 

 dition tun incomplete for description. 



Pyo.ii.hum short, nearly twice as wide as long; outline sub-elliptical; surface 

 convex axiallv, laterally depressed. 



Axis having one-third the width of the shield on the anterior margin, 

 strongly convex, tapering rapidly to a blunt termination close upon the 

 posterior border; bearing nine to eleven annulations, which have a retral 

 bend over the axial line, where the first three or four are thickened and 

 nodose. 



'lip' pleura are Hat for a short distance, thence abruptly deflected and bear- 

 ing seven or eight annulations which are faintly grooved. 



The border is broad, abruptly sloping for one-half its width, and near its 

 inner edge hears a row of conspicuous nodes, which correspond in number 

 and position to the annulations; outside of these the margin is smooth and 

 concave. 



The best preserved specimen of the pygidium has a length of 4 mm., and 

 ;i width of 7.5 nun. 



This species is well defined by the characteristic row of nodes upon the 

 border, a feature which has been observed in many specimens and is undoubt- 

 edly persistent. 



