﻿COCCOSTEID^. 279 



anterior lateral borders being notched by the orbits (o.) and the 

 front border somewhat rounded. A large quadrangular median 

 occipital element (m.o.), and a flanking pair of triangular exocci- 

 pitals (e.o.) form the posterior and the greater part of the postero- 

 lateral borders ; the median occipital tapering anteriorly somewhat 



»z. 



Outline of cranial and dorsal shield of Coccosteus decipiens, Ag., restored by 

 E. H. Traquair. — a.d.l., anterior dorso-lateral : a.L, anterior lateral ; c, cen- 

 tral: e., ethmoid; e.o., external occipital; ra., marginal; m.d., median dorsal ; 

 m.o., median occipital ; mx„ maxillo-suborbital ; ft.,narial opening ; o., orbit ; 

 p., pineal; p.d.L, posterior dorso-lateral; p.l., posterior lateral ; p.mx., pre- 

 maxilla; p.o., pre-orbital ; pt.o., post-orbital; x., opei'culum (?). 



less than the exoccipitals. Immediately in front of these plates is 

 a pair of central elements (c.) meeting in a wavy longitudinal suture 

 at the mesial line ; while the lateral angles of the shield are formed 

 bv a small pair of quadrangular marginals (m.), wedged in on each 

 side between the exoccipital, central, and postorbital {pt.o.) plates. 

 The last-named element is almost as small as the marginal, and 

 extends partly into the upper border of the orbital notch. A pair 

 of large preorbital plates (p.o.) adjoins the front margin of the 

 centrals and postorbitals, forming the anterior two thirds of the 

 orbital notch* with the antorbital process. These plates meet in the 

 middle line of the shield only for a short space in their hinder half, 



