'i'RII.OrUTES OF THE ChAZV LlMKS'lONK. '.)0'S 



unable to find any important differences between the Chazy trilobite 

 known as IlUcnus arctiiriis and the common Tlialeops ovata Conrad of 

 the Trenton, llheniis vindex Billings (fig. 2) and /. clavifrons 1^\\\- 

 ings are also evidently the same as the Trenton species just mentioned 

 and thus all the individuals of the Tlialeops type found in the Chazy 

 seem to belong to the one species. 



Vu\. 2. Dorsal and anterior view of llliniua 7 iiiiicx Hillings. Reproduced hum 

 ISillings' figures in Paleozoic Fossils of C'anada, volume I. 



The cranitlia and ])ygidia are found everywhere and may easily be 

 recognized, the cranidium by its deep furrows and sjjine like eye lobes, 

 and the pygidium by its sharply outlined axis. 



T^F.SCRll'TIOX. 



Whole animal short and wide. Both cephalon and jiygidium very 

 broadly rounded. 



Cephalon very broad, al)ruj)tly deflected in front with the free 

 cheeks produced into long lateral spines. 



Glabella outlined by broad deep furrows which run about parallel 

 from the posterior margin half way to the front, then turn outward 

 and downward over the front of the cephalon. These dorsal furrows 

 are especially deep and strong on the cast. On the front of the hori- 

 zontal part of the glabella are two slight elevations outlined by indis- 

 tinct furrows, indicating the position of the first pair of glabellar 

 furrows. Xeck furrow visible on the cast, but only seldom seen on 

 the test. Fixed cheeks moderately convex. Eyes rather small, 

 situated high on stalks which extend outward and upward at an angle 

 of about 45°. Free cheeks drawn out into long narrow spines. All 

 around the front is a very narrow striate margin. Surface punctate. 



Thorax often narrow segments which run nearly straight across the 

 body, turning downward and backward on the sides. Axis about 

 one third the width of the dorsal surface and only moderately convex, 

 while the pleura are nearly flat. Segments sparsely marked with 

 punctee which are arranged in straight lines across the thorax, one or 

 two rows to a segment. They are more noticeable on the first two or 

 three segments than on the ones further back. 



