^°i89o!"'j procp:edings of the national museum. 277 



Formation and locality. — Liiuestoue of the Potsdam Terrane, -4 miles 

 west of Saratoga Spriugs, N. Y. Collector, 0. D. W. 

 Nat. Mus. Cat. Invert. Foss., ?38C3. 



Agraulos ? thea sp. nov, 



Plate XXI, Fig. 15, 



Glabella convex ; sides subparallel ; front broadly rounded ; surface 

 marked by three pairs of slightly impressed furrows; occipital segment 

 narrow, transverse, clearly defined by the narrow transverse occii)ital 

 furrow ; dorsal furrow deep all about the glabella. 



Free cheeks subtumid and merging anteriorly into the narrow, 

 rounded frontal limb; palpebral lobe of medium size and situated a 

 little back of a transverse line crossing the center of the head ; pos- 

 tero-lateral limbs short and strongly grooved by the marginal furrow ; 

 frontal limb very short and rounded into the margin. 



The associated pygidium is subtriangular in outline, convex ; median 

 lobe narrow, convex, elevated above the general surface of the pygid- 

 ium ; divided by transverse furrows into eight or nine anchylosed seg- 

 ments ; both the furrows and the segments are carried out onto the con- 

 vex lateral lobes. 



This species occurs with Ptychoparia minor in the lower horizon of 

 the Wisconsin Upper Cambrian section. The characters of the head 

 and pygidium are such that the species is referred provisionally to 

 Agraulos. 



Formation and locality. — Upper Cambrian (Potsdam Terrane). Osce- 

 ola JMills, Wis. (Collector, Dr. Cooper ('urtice, 



Nat. Mus. Cat. Invert. Foss., 23864. 



Illceniirus ? dia sp. jiov. 

 Plate XX, Fig. 6, 



Glabella subquadrangular, convex, a little longer than wide and 

 curving downward in front to the slightly arched margin; occipital 

 furrow shallow, arched a little forward midway; occipital segment flat 

 and practically a backward continuation of the glabella ; dorsal furrows 

 clearly impressed. Fixed cheek narrow ; palpebral lobe rather long, 

 separated by a narrow furrow from the cheek ; posteriorly the cheek 

 passes into the postero-lateral limb, the most of which is broken away ; 

 anteriorly it merges into a rather broad subtriangular expansion that 

 extends from the palpebral lobe to the frontal margin. Surface appar- 

 ently smooth. 



This little head is distinct from any known to us. It appears to be 

 a link between Illa3nurus and Bathyurus, or rather some of the species 

 placed in the latter genus. 



Formation and locality. — Upper Cambrian (Potsdam Terrane) Mor- 

 gan's Creek, Burnet County, Texas. ColItM-tor, (J. 1). W. 



Nat. Mus. Cat. Invert. Foss., 33805. 



