365 



sisting of two obscurely developed triangular or sub-ovate lobes. The 

 specimen, however, is not well preserved in this part. Surface, appar- 

 ently smooth. 



Length of the only specimen collected 8 lines ; width at the anterior 

 margin 11 lines ; width of the axis at the anterior margin 3 lines. 



It is scarcely possible to separate this species from B. extans of the 

 Black River limestone. The axis is more distinctly segmented, and this 

 is the only difference exhibited by the specimen. 



It may be that this is the pygidium of a species of Olenellus or Bikelo- 

 cephalus, both of which genera are evidently allied to Baihyurus. 



Locality and Formation. — B, east arm of Bonne Bay, Newfoundland ; 

 Potsdam group. 



Collector. — J. Richardson. 



Bathyurus vbtulus. (N. sp.) 



Description. — Pygidium semi-circular, obtusely rounded behind, length 

 about half the width, rather strongly convex. Axis cylindrical, strongly 

 convex, with three segments (besides the half segment), in the anterior 

 two-thirds, the posterior third, smooth. Side lobes with three broad con- 

 vex segments (besides the half-segment at the margin), a narrow smooth 

 border all round. Surface apparently with fine tubercles. 



This species differs from the last in its more obtuse form and more con- 

 vex segments. 



Length 6 lines ; width at the anterior margin 12 lines. 



Locality and Formation. — B, east arm of Bonne Bay, Newfoundland ; 

 Potsdam group. 



Collector. — J. Richardson. 



Besides the species of trilobites above noticed there are fragments of a 

 number of other species probably all new. 



In the Potsdam group, in B and C, Olenellus Thompsoni occurs in vast 

 abundance, but no entire specimens were collected. In 0. Oonocephalites 

 Teucer, and O. Adamsii (ante p. 11), were also found. 



In the following catalogue, there are several species, such as, — Scoli- 

 thus linearis, Palceophycus incipiens, and some others, which were col- 

 lected on the north shore of the Straits of Belleisle ; on the east side, and 

 also in the southern part of Newfoundland, in rocks which have not yet ' 

 been strictly identified with any of the divisions. Their position is, there- 

 fore, not indicated in the columns : — 



