274 ROYAL SOCIETY OF CANADA 
PLATE IV. 
PHLYCTANASPIS ACADICA-—(page 265). 
After Traquair and Smith Woodward. 
Figure 1—Copy of Traquair’s restored outline of the cranial shield 
of this species, in the Geological Magazine for February, 
1890. p.L., postero-lateral angle; P.E., postero-external 
angle; A.E., antero-external angle; P.0., postorbital 
angle; A.0., ante-orbital angle; m. 0., median occipital ; 
e. o., external occipital; c., central; m., marginal; pt.o., 
post-orbital; p.o., pre-orbital. 
Figure 2.—Reproduction of A. Smith Woodward’s figure of a specimen 
of P. Acadica, in the Geological Magazine for January, 
1892. In this specimen the head shield has been “ crushed 
in such a manner as to separate its component elements.” 
c., central; e., ethmoid; e. 0., external occipital; m., mar- 
ginal; m.o., median occipital; p., pineal; p.mz., pre- 
maxilla; p.o., pre-orbital; pt. o., post-orbital. 
Figure 3.—“ Visceral aspect” of the ethmoidal (e) and pineal (p) 
plates of the cranial shield of another specimen, showing 
the “ great pineal pit at the hinder angle of the ‘ rostral ? 
plate.” Also-from the Geological Magazine for January, 
1892. 
Figure 4.—Copy of Traquair’s “restoration of the ventral carapace ” 
of P. Acadica, in the Geological Magazine for April, 1893. 
a.v.l., anterior ventro-lateral plates; p.v.1., posterior 
ventro-lateral, not defined in the outer margin in the 
fossil; a.m.v., anterior median ventral; m.v., median 
ventral; i./., interlateral; c., cornu or lateral spine. 
