THE OTTAWA NATURALIST 



VOL. XXIV. OTTAWA, NOVEMBER, 1910 No. 8 



ON TWO NEW TRILOBITES FROM THE CHAZY NEAR 



OTTAWA.* 



By Percy E. Raymond. 



Bathyurus superbus Sp. Nov. Plate II, Figs. 1 3. 



Entire test broadly oval in outline, the breadth varying 

 from .6 to .8 of the length. Dorsal furrows deep on thorax and 

 pygidium, but shallow on the cephalon. Axial lobe narrow and 

 rather low, not being raised much above the general level of the 

 surface. 



Cephalon short and wide, surrounded by a very narrow 

 concave border. Glabella nearly smooth, expanding slightly in 

 front of the eyes; marked by two pairs of faint furrows. Eyes 

 very large, low, extending back to the neck furrow and forward 

 to the middle of the glabella. Free cheeks wide, convex, the 

 genal angles drawn out into spines which extend back to the 

 fifth or sixth segment of the thorax. Surface of the test smooth 

 except for fine striae which are rather prominent on the inner 

 margin of the free cheek. 



Thorax of nine segments. Axial lobe narrow. Ple^ira with 

 deep furrows. 



Pygidium nearly semicircular in outline, with a broad con- 

 cave border and a low, smooth axial lobe. The pleural lobes are 

 marked by four pairs of wide, unfurrowed ribs which can be 

 traced across the concave border. The axial lobe is crossed by 

 one prominent ring, and two fainter ones. Behind the rings are 

 a series of pairs of hardly visible pits. Test covered with faint 

 irregular striae. 



The hypostoma i.-; about as broad as long, almost straight 

 in front, sem.'^ircular behind; muscular attachments in front of 

 the middle; side wings narrow. It is very similar to the hypo- 

 stoma of Bathyurus extans, but broader in front. 



Length of the largest specimen 74 mm., width 58 mm. A 

 smaller specimen is 40 mm. long and 25 mm. wide. One pygi- 



* Published by permission of the Director of the Geological Survey of Canada. 



