RAYMOND! SOME \i.u ORDOVICIAN rRILOBITES. 281 



Cephalon somewhat irregular In outline, the glabella projecting in front of 

 the cheeks. Glabella long and wide, with a very narrow circumglabellar fur- 

 row and a very narrow upturned border. There are two pairs of glabellar 

 furrows which run inward and somewhat backward and arc deeply impressed, 

 particularly at their inner ends. Fixed cheeks narrow, with a somewhat wide 

 convex marginal border which extends around the Bides and connects with 

 the neck-ring. \ truncation of this border at the sides suggests the possible 

 former presence of very narrow free cheeks, hut there arc no traces of palpe- 

 bral lobes. 



'Thorax with (apparently) eleven segments. Axial lobe wide and the rings 

 smooth. 



Pygidium Strongly segmented, with about six pairs of ribs on (lie pleural 

 lobes and seven rings on the axial lobe. 



Measurements: — Length, 11.5 mm. Length cephalon, 3.5 mm., thorax, 

 ")..") nun., pygidium, o mm. Width at genal angles, 6 mm., width glabella, 

 3 mm., width axial lobe at front 2.75 mm., width pygidium 4 mm. 



This species can be distinguished from all others by the absence 

 of eyes. The most closely allied species is Triarthrus humilis Hadding 

 which has the eyes far forward and the free cheeks very narrow. 



Horizon and Locality: — A rather common species in the Athens 

 shale in the Catawba valley north of Salem, Va., where the type was 

 collected by Prof. S. L. Powell, and also at Laskers Gate, three miles 

 northeast of Blacksburg, Va., w T here it was collected by Dr. R. M. 

 Field and the writer. A few specimens were also found at Saltville, 

 Va., near the base of the Athens. Holotype M. C. Z. 1,593. 



Remopleuridae Corda. 



ROBERGIA MAJOR, Sp. nOV. 



Cephalon large, rounded in front, wider than long, with long narrow spines 

 at the genal angles. 



Glabella elongate, a little expanded in front of the long eyes, with three pairs 

 of furrows on the wide portion between the eyes. In front of the glabella 

 there is an extremely narrow flattened border. Free cheek narrow, extended 

 backward into a narrow spine of about its own length. 



Hypostoma bifurcated, with two very long prongs, as in Remopleurides. 



Thorax known from two incomplete specimens, the larger with nine seg- 

 ments. Judging from these specimens the thorax is long, narrow, with very 

 little taper. The axial lobe is wide, convex; the side lobes flat and narrow, 

 the individual segments ending in short spines. 



Pygidium nearly square, as long as wide, sides straight and slightly con- 

 vergent. Axial lobe elevated, extending three fourths of the length, wide 



