90 



WKALDEN AND PURBBCK FOSSIL FISHES. 



Family AMiiDiE. 



Genus AMIOPSIS, Kner. 



Amiopsis, It. Kuer, Sitzungsb. \z. Akacl. Wiss. Wien, math.-naturw. CI., vol. xlviii, pt. i, 1863, p. 126. 



Generic Characters. — Trunk elongate and laterally compressed. Head large; 

 all the marginal teeth large and conical, but those of the dentary largest ; inner 

 teeth smaller; maxilla laterally compressed and deepened behind. Vertebral 

 centra completely ossified in the adult, biconcave, the hypocentra and pleurocentra 

 forming distinct alternating discs in the caudal region ; each centrum impressed 

 with three or more extended pits on its side; ribs short. Fins without fringing 

 fulcra, the rays articulated and branching; dorsal fin occupying not more than 

 one-third of the back ; anal fin small and short-based ; caudal fin with convex 



Fig. 29. — Amiopsis dolloi, Traqnair ; restoration, showing scales, much reduced in size. — Wealden ; Hernissart, 



Belgium. After K. H. Traquair. 



hinder border. Scales almost oval in shape, the long axis horizontal ; exposed 

 portion thickened. 



Type Species. — Amiopsis prisca (R. Kner, loc. cit., I860, p, 126, pi. i), from the 

 Cretaceous of Mrzlek, valley of the Isonzo, Istria. 



Remarks. — This genus was not satisfactorily defined until 1895, when 

 Kramberger described well-preserved specimens of the typical species (Djela 

 Jugoslav. Akad., vol. xvi, p. 12, pi. iii, fig. 2, pi. iv). The pittings in the side of 

 the vertebral centra distinguish it from Megalurus (L. Agassiz, Poiss. Foss., 

 vol. ii, pt. i, 1833, p. 13), which occurs typically in the Lithographic Stone (Lower 

 Kimmeridgian) of Germany, and has also been found in the Lower Cretaceous 

 of Bahia, Brazil (Megalurus mawsoni, A. S. Woodward, Ann. Mag. Nat, Hist. [7] 

 vol. ix, 1902, p. 87, pi. ii). Two species, Amiopsis dolloi (Text-figs. 29, 30) and 

 J. hi t<i, from the Wealden of Bernissart, Belgium, have been described by R, H. 

 Traquair, Mem. Mus. Roy. d'Hist. Nat. Belg., vol. v, 1911, pp. 37, 42, 

 pis. vii, viii. 



