576 
ACTIIfOPTEEYGIl. 
hispiclus, G. S. Yolta, Ittiolit. Yeronese, 1796, p. xxxv. 
pi. viii. fig. 3 {errore). Tetrodon lionckenii, G. S. Yolta, 
ibid. p. xxxiii. pi. viii. fig. 2 {errore). —Tipper Eocene ; 
Monte Bolca. [Imperfect small fish, probably not showing 
pelvic fins ; Paris Museum of Natural History.] 
Genus ORTHAGORISCUS, Bloch & Schneider. 
[Syst. Ichthyol. 1801, p. 510 {Ortliragorisciis).'] 
Trunk much laterally compressed, truncate behind. Each jaw 
fused at symphysis, without dental plates. Dorsal and anal fins 
acuminate in front, meeting round the atrophied tail. No dermal 
armour. 
The species of this genus attain a very large size, and are 
almost unknown among fossils. 
The undescribed Ortliagoriscus chelonopsis (P. J.Yan Beneden, Bull. 
Acad. Boy. Belg. [3] vol. vi. 1883, p. 133), from the Pliocene Crag 
of Antwerp, is represented by large typical jaws in the Brussels 
Museum. The so-called jaw of Ortliagoriscus recorded from the 
Sussex Chalk by E. Dixon (Geol. Sussex, 1850, p. xiii. pi. xxxii. 
figs. 3, 4) seems to be a Chelonian dentary bone (A. S. Woodward, 
Proc. Geol. Assoc, vol. x. 1888, p. 276). 
The following specimen probably belongs to this genus:— 
P.9088. Portion of typical jaw; Patagonian Eormation, Chubut, 
Argentine Bepuhlic. Purchased, 1899. 
Division E. SC0IlP.®NIF0IlMES. 
Pectoral fins with much extended base on flank; pelvic fins 
thoracic, never with more than five articulated rays in addition to 
the spine. One bone of the circumorbital ring modified into a bony 
stay between it and the armoured preoperculum. 
Synopsis of Families represented by Extinct Genera or Species. 
I. Post-temporal hone free, and supraclavicle 
normal. 
Abdominal vertehrse with transverse processes 
bearing ribs ; 3 anal fin-spines ; scaly or 
naked . Scobp^nid.® (p. 577). 
Yertebral transverse processes not bearing the 
ribs ; no anal fin-spines; scaly or naked. Cottid^ (p. 580). 
