84 



WEALDEN AND PURBECK FOSSIL FISHES. 



The skull must have measured originally about 10 cm. in length, but the 

 parietal and occipital regions are missing. The remains of the thick rugose 

 frontal bones (fr.) show the usual deep interdigitation of their median suture in 

 the region between the postfrontals (sphenotics). The tapering anterior end of the 

 narrow squamosal is also seen bordering the hinder end of the frontal on the left 

 side (sq.). The cheek-plates are marked with a finer rugosity than that of the 

 cranial roof, with some tuberculation. Both the postorbitals ( so.) are imperfect, 

 but the lower seems to be the larger, its subdivision not being clear. The postero- 



sm-x. 



Fig. 28.— Caturus latidens, sp. nov. ; imperfect head, upper (A), left side (B), and lower (C) views, two- 

 tliirds nat. size, with upper (D) and lower (E) teeth enlarged twice. — Wealden ; Hastings, Sussex. 

 Beckles Collection (B. M. no. P. 6360). br., branchiostegal rays ; co., posterior circumorbital ; fr., 

 frontal; gu., gular ; mx., maxilla; orb., orbit; smx., supramaxilla ; so., postorbitals; spo., sphenotic 

 (postfrontal) ; sq., squamosal. 



superior circumorbital (co.), as usual, is deeper than wide, and there seem to be 

 remains of the irregular superior circumorbitals. One of the antorbitals, a 

 little displaced, is an elongated irregularly rhomboidal plate. The maxilla (mx.) 

 exhibits the ordinary constriction near its anterior end, and is not much deepened 

 behind ; its outer face is comparatively smooth, marked only by a few irregular 

 longitudinal grooves. Its hinder end was originally bordered by a single narrow 

 supramaxilla, similarly ornamented, which tapers to a point in front (smx.). Most 

 of the maxillary teeth are broken away, exposing their very large pulp-cavity. 



