io 4 ELOPIFORM FISHES 



into a groove along the posterior margin of the ectopterygoid. This latter element 

 is boomerang-shaped, with unequal limbs directed postero-ventrally and antero- 

 dorsally. The anterior tip of the ectopterygoid fits into a small recess on the pos- 

 terior aspect of the autopalatine. Small villiform and rounded teeth are borne along 

 the entire buccal surface of the ectopterygoid. The anterior teeth are comparable 

 in size to those on the parasphenoid, but posteriorly they become smaller. 



The endopterygoid is large. Its convex buccal surface is covered with many small 

 teeth. Posteriorly it is overlapped by the metapterygoid, anteriorly it contacts the 

 autopalatine, while laterally it sutures with the ectopterygoid. 



The autopalatine ends anteriorly in a transversely expanded condyle. This 

 condyle contacts a process upon the maxilla laterally and presumably lay against 

 the cartilaginous ethmoid medially. The dermopalatine is represented by a large 

 oval tooth plate which bears similar teeth to those on the endopterygoid and anterior 

 region of the ectopterygoid. 



Dermal upper jaw. The upper jaw extends from the snout to the level of the 

 quadrate/mandibular articulation. The ventral margin is convex. All bones are 

 heavily ornamented with coarse rugae. 



The premaxilla is tapered both anteriorly where it fits against the dermethmoid 

 and posteriorly where it fits into a notch on the lateral face of the maxillary head. 

 The premaxillae just meet in the mid-line, and form about 38 per cent of the upper 

 jaw border. A broad band of many small villiform teeth is present on the pre- 

 maxilla. 



The maxilla ends anteriorly in a simple point where it lies against the ethmoid. 

 A little further back the dorsal surface is raised in a small knob which articulated 

 with the palatine head, probably through a biconcave sliver of cartilage, as in elopoids. 

 The posterior end of the maxilla becomes slightly deeper where it is partially overlain 

 by the supramaxillae. Teeth similar to those on the premaxilla occur along the 

 entire oral margin of the maxilla. There are two supramaxillae set in tandem. The 

 anterior supramaxilla is oval and overlain along much of its dorsal margin by a 

 projection of the posterior element. 



Mandible. The mandible is slightly longer than the upper jaw. The greatest 

 depth of the mandible occurs at the coronoid process, situated at two-thirds of the 

 mandibular length from the symphysis. The dentary forms the anterior two-thirds 

 of the mandible. From the inturned symphysis the bone expands vertically and 

 bears a narrow horizontal ledge along the ventral margin. Beneath this ledge is a 

 line of 20-25 small pores set at regular intervals along the entire length of the dentary. 

 The mandibular sensory canal ran within the articular posteriorly and the dentary 

 anteriorly and communicated with the exterior via these pores. The posterior 

 margin of the dentary has the shape of a lazy ' V ', the apex directed towards the 

 symphysis. Medially the articular partially overlapped the dentary, there being 

 a gap between these elements, the Meckelian fossa, which received the anterior 

 extension of the A w division of the adductor mandibulae. The oral surface of the 

 dentary bears a broad band of villiform teeth. 



The articular forms the posterior half of the coronoid process and the extreme 

 outer edge of the articulatory cup. Ornamentation on the articular is confined to 



