Carboniferous Trilobltes. 103 



lobe ornamented with tubercles, arranged so as apparently to form five lon- 

 gitudinal rows ; pleune each provided with two nodes, arranged so as to form 

 two rows along each lateral lobe, those of the outer row being a little larger 

 than the others, and situated somewhat within the middle of each lateral 

 lobe at the point where the pleura? bend to form the slope of their lateral 

 extremities. Pygidium semi-elliptic, with length and breadth as three to 

 four, very convex ; mesial lobe very prominent and equaling more than one- 

 third the entire breadth of the anterior end, rather rapidly tapering back- 

 wards to an obtuse, prominent termination before quite reaching the poste- 

 rior margin, provided with 12 or 10 segments, each one of which bears five 

 little nodes arranged so as to I'oi-m five rows, those of the middle row being 

 larger and more prominent than the olliers, and thus giving the lobe a cari- 

 nated npiiearance ; lateral lobes somewhat fiatlened above for about half 

 ihcir breadth, at which point they bend suddenly downward for a short dis- 

 tance, and then obliquely outward to form a rather broad sloping border, 

 each provided with 7 or 9 segments, the posterior of which are obscure and 

 directed nearly backwards, the segments each bearing 2 or 3 little nodes 

 arranged so as to form as many longitudinal rows, and all continued dowm 

 upon and across the sloping border, at the edges of which they terminate 

 in little pointed projection* so as to present a fimbriated appearance around 

 the posterior and lateral edges. 



Length, 0.49 inch ; breadth, 0.28 inch ; length of cephalic shield, 0.20 

 inch ; do. of a pygidium of another specimen from Loudonville, 0.23 inch. 

 in length by 0.30 inch, in breadth, with a height (of mesial lobe) of 0.10 

 inch. 



Position imd locality, Cuyahoofi shales, at Lodi, Medina Co., 

 Ohio, and Waveily group at Loudonville, Ohio ; Lower Carbon- 

 iferous. 



Mr. Meek compares the head of this species with BracJiymeto- 

 piis MacOoyi, Portlock, and remarks that ^'its eyes, however, 

 are proportionally smaller, its occipital ridge much more strongly 

 developed and wider, while the tubercles of its marginal rows are 

 not nearly so crowded as in Portlock's species." 



We have examined a specimen of this species from the Cuya- 

 hoga shales of Lodi, Ohio, now in the museum of Columbia Col- 

 lege. The pygidium is semi-elliptic in form, the axis has 12 

 segments, with indistinct rows of nodes ; the side-lobes are 

 marked with 6 ribs each, extending to the margin of the pygi- 

 dium. 



The pygidium of Brachy^netopus MacCoyi, has 15 coalesced 

 segments on the axis, each segment having about five small tu- 

 bercles on the axis, and about as many on the 8 simple lateral 

 lobes ; ribs ending abruptly near the margin of pygidium. 



