Vol. 6$.~\ CRETACEOUS FOSSILS FROM BAHIA. 135 



fig. 4 a), preserved in a fragment of another skull, shows that this 

 element was similarly ornamented with longitudinal ridges, which 

 diverge and multiply backwards, while they tend to become irre- 

 gularly nodose, and even ramify into a network. The parietal 

 bone, as usual in Coelacanths, is much wider behind than in front, 

 and meets its fellow of the opposite side in a straight median suture. 

 Its thickened and slightly - wavy anterior border, which would 

 articulate with the frontal, is curiously excavated by a groove, 

 which causes the outer and inner laminae of the bone to overhang 

 the thick middle lamina (fig. 4 b). The pterygo-suspensorial arcade 

 (pts.) forms the usual irregularly-triangular plate of bone, in which 

 no suture can be distinguished. The quadrate (PI. VII, fig. 3) 

 terminates below in a very stout ginglymoid articulation for the 

 mandible, its outer condyle being much smaller than the inner 

 condyle. The postero-external margin of the quadrate, directly 

 above its outer condyle, is coarsely rugose, as if for loose union 

 with a superficial plate of bone. In some respects, the articular 

 end of this element resembles that of a pterosaurian quadrate ; and 

 I was once misled by the similarity in question to describe one of 

 Mr. Mawson's specimens as probably referable to a gigantic ptero- 

 dactyl. 1 The upper end of the hyomandibular (Am.) is much 

 expanded forward, so that it is not only firmly fixed to the ossified 

 otic mass, but must also have had an extensive articulation with 

 the unossified postfrontal (or sphenotic), which is represented by a 

 vacant space in the fossil. The entopterygoid and ectopterygoid 

 (pt.) form a very thin lamina, tapering to a point in front. Its 

 lower margin is quite smooth ; its inner face (PI. YIII, fig. 4 a) 

 is covered, however, with minute tubercular teeth, which are not 

 enlarged towards the border, but are all rounded or bluntly conical, 

 and invested with enamel, which is finely sculptured with delicate 

 lines radiating from the apex (fig. 4 b). The most conspicuous 

 bone of the mandible is the angular (PI. VII, fig. 1, ag.), which 

 must have extended for considerably more than half the length of 

 each ramus. It is deepest just in advance of its middle point, 

 where it rises into an acute coronoid eminence. Its anterior half 

 tapers more rapidly than its posterior half, and two facettes show 

 that it must have been overlapped and underlapped in front by the 

 dentary and infradentary bones respectively. Its outer face is 

 ornamented with longitudinal ridges, like those of the cranial roof, 

 which have mainly a longitudinal direction, although slightly 

 radiating upwards into the feebly-sculptured coronoid region. These 

 ornamental ridges are not tuberculated or enamelled, and they 

 scarcely form any reticulations. The articular bone (PI. VII, 

 fig. 1, art. & PI. VIII, figs. 1 a & 1 b) is a separate element, uniting 

 in squamous suture with the inner face of the angular, just behind 

 the coronoid elevation. It is relatively small, short and stout, and 

 well ossified, with two distinct facettes for exact articulation with 



1 A. S. Woodward, ' On the Quadrate Bone of a Gigantic Pterodactyl dis- 

 covered by Joseph Mawson, Esq., F.G-.S., in the Cretaceous of Bahia, Brazil ' 

 Ann. & Mag. Nat. Hist. ser. 6, vol. xvii (1896) pp. 255-57. 



