250 ROYAL SOCIETY OF CANADA 
A few weeks later, Mr. T. C. Weston, who was then a member of the 
staff of the Geological Survey of Canada, collected an additional number 
of fine specimens of this and of other species at the same locality. It 
was upon the material obtained by Dr. Ells and Mr. Weston in 1880 
that the original description of Pterichthys (Bothriolepis) Canadensis, 
in the American Journal of Science was based. The description ani 
illustrations of this species in the Transactions of this Society for 1886 
and 1888, were based upon the collections made by Dr. Foord in 1880-83, 
as well as upon those previously made by Dr. Ells and Mr. Weston. 
The specimens subsequently studied by Dr. Traquair, Dr. Smith 
Woodward and Professor Patten, have thrown much new light on the 
structure of this species. 
In the Annals & Magazine of Natural History for December, 1888, 
Dr. Traquair has shown that some of the supposed sutures on the exterior 
of the cranial shield of this species, as represented by the present writer, 
on Plate vi, fig. 1, of the Transactions of this Society for 1886, are mere 
superficial grooves, occupied by part of the lateral canal system. And, 
a more correct restoration, in outline, of the dorsal aspect of the cranial 
shield of B. Canadensis, from specimens in the Edinburgh Museum, is 
given on Plate xviii, fig. 6, of Dr. Traquair’s paper. In this restor- 
ation, the number of plates on the dorsal side of the cranial shield of 
the Canadian Bothriolepis is considerably reduced. 
In the Geological Magazine for November, 1892, page 484, Dr. 
Smith Woodward gives a new figure of the two “ maxillary plates ” of 
the under surface of the head of B. Canadensis. 
In a paper entitled “ New Facts Concerning Bothriolepis,” published 
in the Biological Bulletin of the Marine Biological Laboratory, Wood’s 
Holl, for July, 1904, Professor Patten gives a “ reconstruction of 
Bothriolepis,’ as seen from the side, with a median section thereof, and 
other figures, all based upon Canadian examples of this species. This 
important reconstruction is here reproduced on Plate IT. 
The trunk (Professor Patten writes) “was very slender and co- 
vered with a soft skin devoid of scales, or of any other markings except ” 
the following........ “A few small irregular plates with the typical 
sculpture of the buckler, are imbedded in the skin along the dorsal 
surface, immediately in front of the anterior dorsal, and numerous 
minute ones are scattered irregularly over the flanks in the same 
LOSI ONE! ain nay eee “The anterior dorsal fin is low and elongated, the 
posterior one very high and rounded.” The tail, as Traquair writes, 
in reference to this reconstruction, “ was clearly composed of soft tissues, 
with the exception of a row of short, slender rod-like bodies extending 
along the dorsal margin of the heterocercal caudal fin, and another 
