42 NEW YORK STATE MUSEUM 



Dorsal furrows distinct, broad and deep, narrowing forward and 

 extending to the fi*outal border. Fixed cheeks slightly promi- 

 nent. trai>ezoidal in outline, nearly flat in the miBdle part and 

 bending rather abruptly into the dorsal furrow and to the 

 marginal border; each cheek provided with an " eye line," which, 

 arising in the dorsal furrow below the first glabellar pit, extends 

 in the direction of the genal angle, culminating near the middle 

 of the cheek in an eye tubercle and becoming then indistinct. 

 Occipital furrow broad and shallow, widening on either side of 

 the glabella. Occipital ring a uniformly narrow ridge which in 

 the axial lobe rises to a semicircular plate (base of spine?). 



Surface of glabella coarsely pitted; cheeks pitted along the 

 border and strongly reticulate in the middle. The meshes of the 

 reticulation are largest on the cheeks; dorsal furrows and occipi- 

 tal ring smooth. Marginal border in front of the glabella inclined 

 to base at an angle varying between 80^ and 90°, but becoming 

 less inclined posteriorly; in front of the cheeks for about half of 

 its width moderately convex, then equally concave with the mar- 

 gin upturned. The convex i>ortion of the border in front of the 

 glabella is occupied by four concentric rows of circular funnel- 

 shaped perforations, which posteriorly increase by interplanta- 

 tiou to seven or more rows; the concave portion bears a row of 

 radiating elongated perforations^; the rows of perforations are 

 separated by filiform, strongly projecting concentric ridges, 

 which toward the genal angles become less distinct. 



Free cheeks not observed. 



Thorax not well preserved, apparently consisting of six seg- 

 ments, axis broad, moderately convex, decreasing in width more 

 than one third; axial grooves shallow; pleurae not observed. 



Pygklium roundish subtriaugular, with an axis in a small speci- 

 men that is broad at the beginning, slightly tapering and ending 

 bluntly; more acutely tapering in larger sfjecimens; the small 



1 Dr D.-P. Oehlert has demonstrated In bla valuable paper entitled: Sur las Trlnucleus de I'Ouest 

 de la Fran<^e (Soc. gv'-ol. de France. Bui. 3e s^rle. 1895. 23. p. 29*i) that the apparent perfora- 

 tions of the limb of TrlnucleuB are only the reeult of an unfavorable preservation; and that, In fact, 

 the limb or doublure of Trlnucleus \s Imperforate, but i)088es8es cavities, produced by the Inva^na- 

 tlon of the tegument of the limb. Ab the tegument mostly falls of perfect pre.servatlon, these 

 double-conical caTltlee appear opened at their dorsal and ventral apexes. 



