94 WEALDEN AND PURBECK FOSSIL FISHES. 



which some of the anterior scales have the pittings filled with matrix, as drawn 

 somewhat diagrammatically in Egerton's original enlarged figure. 



It maybe added that in the type specimen some well-fossilised ova are scattered 

 in the abdominal region. 



Horizons and Localities. — Lower and Middle Purbeck Beds : Bincombe and 

 Portland, near Weymouth, Dorset. 



A larger form of this or another Amioid species is represented by isolated jaws 

 in the Lower Purbeck Beds of Portland. A right maxilla, lacking teeth, is shown 

 in outer view in PI. XIX, fig. 7 ; while a left mandibular ramus, lacking the tips 

 of the teeth, is shown from the inner aspect in PI. XIX, fig. 8. As usual in true 

 Amioids a few of the anterior teeth in the maxilla associated with the latter 

 specimen are stouter than the others. 



2. Amiopsis austeni (Egerton). Text-figure 31. 



1858. Meyalurus austeni, P. M. Gr. Egertou, Figs, and Descript. Brit. Organic Remains (Mem. G-eol. 



Surv.), dec. ix, no. 9, pi. ix. 

 1858. Attoikeopsis (?) austeni, V. Thiollicre, Bull. Soc. Geol. France [2], vol. xv, p. 785. 

 1895. Megalurus damoni, A. S. Woodward, Catal. Foss. Fishes, B. M., pt, iii, p. 366. 



Tijpe Specimen. — Imperfect head and abdominal region ; British Museum. 



Specific Characters. — Imperfectly known, but head smaller, abdominal region 

 deeper, and flank-scales deeper than in M. damoni. 



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

 somewhat distorted type specimen (Text-fig. 31). The other fragments, mentioned 

 by Egerton as abundant, are evidently referable to Leptolepidae. Traces of stout 

 styliform teeth, with a blunt apex, sometimes slightly curved, are seen in both jaws. 

 Remains of the opercular apparatus, much broken, are exposed from within, and a 

 few broad branchiostegal rays occur below them, with the greater part of the 

 supporting epihyal and ceratohyal (ch.). The vertebral centra clearly exhibit 

 their lateral pitting, and the short curved ribs are observed to be rather stout. In 

 the anterior part of the caudal region, only alternate centra bear arches. The 

 paired fins are very imperfect, but remains of both occur nearly in their original 

 position, the pectorals being especially large. The dorsal fin has the usual three 

 or four gradually lengthening basal fulcra at its origin. The small anal fin is only 

 partly shown in impression. The comparatively deep scales, with rounded posterior 

 border, are best seen in the upper anterior part of the abdominal region. As in 

 the type specimen of A. damoni, there seem to be some fossilised ova. 



Horizon and Locality. — Middle Purbeck Beds : Swanage, Dorset. 



