38 FOSSIL FISHES OF THE ENGLISH CHALK. 



palatine thickened but antero-posteriorly elongated and pointed in front, with two 

 much-enlarged, well-spaced teeth, which are laterally compressed ; ectopterjgoid 

 less stout, with a close series of smaller but similar laterally compressed teeth ; 

 mandible constricted at the symphysis and without external ornament, the dentary 

 bearing a single series of laterally compressed teeth, of which those in the middle 

 are the largest. 



Type Species. — Apateodus ghjphodus (A. S. Woodward, torn, cit., p. 258, pi. xiii, 

 figs. 3 — 5), from the English Grault. 



Remarks. — This genus is known only by the head, of which the upper jaw was 

 wrongly interpreted in the original diagnosis of 1901. The relatively small pre- 

 maxilla and maxilla were at that time overlooked, while the palato-pterygoid arcade 

 was described as the premaxilla. The true premaxilla, bearing a regular series of 



Fig. 8. Odontostomus hyalinus, Cocco ; reduced from nat. size. — A representative of the Odontostomidae 

 existing in Mediterranean. After Giinther. 



very small teeth, is best displayed in a fine skull from the Danian of Maastricht in 

 the Brussels Museum (L. Dollo). 



1. Apateodus striatus, A. S. Woodward. Plate XI, figs. 1 — 7 ; Text-figure 9. 



(?) 1837-44. Saurocephalus striatus, L. Agassiz, Poiss. Foss., vol. v, pt. i, p. 102, pi. xxvc, 



figs. 17—20. 

 1850. Saurocephalus striatus, F. Dixon, Geol. Sussex, p. 375, pi. xxxv, fig. 5. 

 1901. Apateodus striatus, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, p. 260, pi. xiii, fig. 6, 



pi. xiv. 



Type. — Small head from a Turonian zone ; British Museum. 



Specific Characters. — A species known only by the head, with mandible probably 

 attaining a length of about 15 cm. The anterior enlarged palatine tooth about 

 two thirds as long as the posterior tooth, and the length of the latter equalling the 

 interspace between the two teeth, also about half the length of the part of the 

 palatine in front of its insertion. Maximum depth of mandible equalling about one 

 fifth of its length ; dentition occupying half its length, with two relatively large 

 teeth of about equal size in the middle of the series, with small broad teeth behind, 



