CATURUS. 85 



They are nearly round in section at their base, but, as shown in the righi maxilla, 

 their blunt apex is laterally compressed (Text-fig. 28, D). A cluster of nearly 

 similar teeth, curved and apparently less compressed at the apex, occurs in froni 

 of the right maxilla on a thick piece of bone which may represent the palatine. 

 The mandible is very fragmentary, but its lower border must have been much 

 curved inwards, and its coronoid region rises abruptly into the usual considerable 

 elevation. Its teeth (E) resemble those of the maxilla (D), but seem to be somewhat 

 larger. The gular plate (;/".), which occurs in position between the mandibular 

 rami, is especially large, reaching as far backwards as the hinder end of the tooth- 

 bearing border of the dentary. Traces of the anterior branchiostegal rays (br.) 

 show that they are thick rather than laminar. 



Remarks. — As suggested by the shape of the teeth, it is possible that this 

 species may not belong to Caturus, but to the closely allied genus Callopterus 

 (with a more remote dorsal fin), which has already been recorded from the AVealden 

 of Belgium by R. H. Traquair, ' Les Poissons Wealdiens de Bernissart ' (Mem. 

 Mus. Roy. Hist. Nat. Belg., vol. v, 191 1, p. 34, pi. vi). See Text-fig. 27, p. 83. 



Horizon and Locality . — Wealden : Hastings, Sussex. 



2. Caturus purbeckensis, A. S. Woodward. Plate XIX, figs. 1, 2. 



1890. Strobilodus purbeckensis, A. S. Woodward, Proc. Zool. Soc, p. 350, pi. xxix, fig. 4. 



1895. Caturus (Strobilodus) purbeckensis, A.S. Woodward, Catal. Foss. Fishes Brit. Mus., pt. iii, p. 348. 



Type. — Head ; British Museum. 



Specific Characters. — Head with opercular apparatus usually attaining a length 

 of from 10 to 15 cm.; external bones without ornament. Maxilla a little curved 

 downwards behind, where its teeth become comparatively small and slender ; teeth 

 of middle of maxilla much deeper than the bone at their insertion. Mandible very 

 slender, pointed, and tending to curve upwards in front ; height of middle dentary 

 teeth nearly equal to depth of the bone at their insertion. All the teeth tumid, 

 often with an external indent, at their base, becoming very slender in their incurved 

 apical half, and tipped by a laterally compressed cap of translucent ganodentine 

 with prominent edges. 



Description of Specimen*. — This species is known only by the imperfect 

 specimen of the head and adjoining parts shown in PI. XIX, fig. 1, and by 

 detached jaws. 



The cranium is so much crushed in the type specimen (PI. XIX, fig. 1) that its 

 characters can only be vaguely seen. The roof-bones are marked by a faint 

 rugosity and numerous irregular fine pittings. The postfrontal (sphenotic) is well 

 ossified ; and the stout parasphenoid, where it crosses the orbit and eventually 

 underlaps the vomers, is a depressed lamina. The postorbital cheek-plates and the 

 large hinder circumorbitals are smooth, exhibiting only very fine scattered pittings 



