Canada 
Geological Survey 
Victoria Memorial Museum 
BULLETIN No. 1 
VIII. A Revision of the Species which have been Referred to the 
Genus Bathyurus. 
Preliminary Paper. 
By Percy E. Raymond. 
Billings erected the genus Bathyurus for trilobites of the type 
of Asaphus extans , Hall, but, in practice, did not adhere to his 
own definition, and described trilobites of all sorts as species of 
Bathyurus. In this, other writers have not been slow to follow 
his example, so that, at one time or another, some 50 species have 
been referred to this genus. The writer now knows of only 12 
species, and 3 of these are described for the first time in this 
paper, which agree generically with the type of this genus. The 
attempt to dispose of the other species has necessarily led to the 
erection of several new genera, only one of which can be retained 
in the Bathyuridm. The work so far done has covered only the 
species described by Billings, and as the assembling and study 
of the other species will cause a considerable delay, it is thought 
advisable to present the more important facts here. The final 
paper will include full descriptions and illustrations of all the 
species. 
Family Bathyuridm, Walcott. 
Genus Bathyurus, Billings. 
Revised Generic Description. — Outline elongate oval, cephalon 
always longer than pygidium. Glabella subconical, expanding 
