A. Smith Woodward — On Eurycormm. 291 



truncated behind but rapidly tapering to a point in front, and with a 

 smooth or only slightly rugose external surface. 



The mandible is much crushed and the symphysis lost, but three 

 of the elements are readily distinguishable. A thin, plate-like 

 splenial (Fig. 5, spl.) occupies the inner face, and is provided with 

 small teeth. The deutary (Figs. 1, 5, d.) is the largest bone and only 

 shows the sockets of a single series of relatively large teeth in the 

 anterior portion of its length : it is relatively deep and seems to have 

 been somewhat bent inwards inferiorly. The hinder border of the 

 dentary exhibits a re-entering angle into which fits the anterior 

 pointed extremity of the well-developed angular bone (Fig. 1, ag.) ; 

 this element being longer than deep, with a thickened, smooth, 

 ginglymoid hinder face (Fig. 6), probably for articulation with the 

 inferior extremity of the preoperculum. 



The teeth in both jaws are round in section, relatively long and 

 slender, and may be appropriately described as styliform. 



The membrane bones of the cheek are very large and few in 

 number. A single trapezoidal bone, narrower above than below, 

 occupies the greater part of the postorbital region (Fig. 1, pt.o v ) ; 

 two (or perhaps three) smaller postorbitals bound its inferior margin 

 (pt.o. , 3 ) ; and there is a trace possibly of a small triangular ele- 

 ment at the hinder end of the maxilla and jugal (x). A narrow sub- 

 orbital bar (so.), without distinct sutures, extends along the superior 

 borders of the jugal to a single, large ovoid plate (ao.), which occu- 

 pies the space between the cranial margin and the anterior third 

 of the maxilla. These bones are externally ornamented in part by 

 rugosities, in part by tuberculations. 



The sclerotic is ossified, and fragments are seen on the right side 

 (Fig. 1, scler.). 



The single azygous jugular plate is very large, elongated, and 

 narrow, about two-thirds as long as the mandible ; and immediately 

 behind it are the remains of a few stout, narrow branchiostegal rays, 

 on the right side overlapping a fragment of the ceratohyal. The pre- 

 operculum is shown on the right side in position (Fig. 1, p. op.), 

 very long and narrow and gently arched ; and immediately behind is 

 the large, quadrate operculum (op.). The suboperculum and inter- 

 operculum are unfortunately destroyed, but a fragment of the former 

 is seen on the left side. 



A large triangular supratemporal bone (Fig. 1, st.) occurs above 

 the operculum, tapering towards its apex at the middle of the 

 occiput. A small supraclavicle (s. cl.) and the upper half of the 

 clavicle (cl.) are also recognizable. 



The vertebrae of Eurycormus have already been described by Dr. 

 von Zittel, 1 and it thus suffices merely to note that two examples of 

 the characteristic form (Fig. 7) are seen in the hinder portion of the 

 fossil. The pleurocentra (pi.) and hypocentra (hyp.) are distinctly 

 separated by the oblique lateral suture ; and the inferior element 

 bears a lateral articular facette for a bone of the hasinal arch. 



1 K. A. von Zittel, " Handbuch der Palaeoutologie " (1887), p. 230, fig. 242. 



