EE VISION OP SPECIES REFEREED TO GENUS BATHYURUS 
63 
Pygidlum small, showing three rings on the axial lobe, and 
three pairs of ribs on the pleural lobes. The axial lobe is not 
prominent, as in Proetus and Cyphaspis, but low, triangular, 
and separated from the pleural lobes by narrow furrows, which 
meet behind the axial lobe, thus isolating it. 
Locality.— F rom the Trenton, probably a little above the 
Prasopora bed, at Peterborough, Ont. Collected by Lawrence 
M. Lambe, in 1891. 
Family Dikelocephalidje, Miller. 
Genus Platycolpus nov. 
( platys f broad; colpos, furrow.) 
This genus is proposed for trilobites with hemispheric, rather 
smooth cephalon, a depressed glabella extending to the an- 
terior border, which is a flat, striated rim; glabellar furrows 
faint or absent, eyes small, situated midway on the length of 
the head; facial sutures cutting the posterior margin just 
inside the genal angles, and the anterior margin in front of the 
eye. 
Pygidlum semicircular, without depressed border, and with 
faint traces of segmentation. 
Type: Bathyurus capax, Billings. 
Platycolpus capax (Billings). 
Plate VII, figs. 20 and 21. 
Bathyurus capax, Billings, 1860. Canadian Naturalist and 
Geologist, Vol. V, p. 318, fig. 20. 
This species is common in the conglomerates at Point Levis, 
and is supposed to be upper Cambrian in age. 
Platycolpus eatoni, (Whitfield). 
DiJcelocephalus eatoni, Whitfield, 1878. Annual Report Geo- 
logical Survey of Wisconsin for 1877, p. 65. 
Distinguished from P . capax by the presence of faint glabellar 
furrows. The species is found in the magnesian limestone of 
the Devils Lake district, Baraboo, Wisconsin. 
