360 MEMOIRS OF THE CARNEGIE MUSEUM. 



" Les ecailles proprement dites sont a peu pres indiscernables, bien qu'elles 

 existent: ce qui tient a leur tres-faible epaisseur; mais on reconnait a la loupe, que 

 la surface du corps est parsemee de petites epines fort aigues, disposees par zones 

 qui doivent correspondre au bord posterieur des ecailles " (ThioUiere, I. c, p. 10). 



Order ACTINOPTERYGII. 



Suborder PROTOSPONDYLI. 



Family SEMIONOTID^. 



"Trunk more or less deeply fusiform, rarely cycloidal. Cranial and facial 

 bones all robust and opercular apparatus complete, but branchiostegals sometimes 

 reduced; parietals meeting in the middle line; mandibular suspensorium vertical 

 or inclined forwards, and gape of mouth small; teeth styliform or tritoral, especially 

 well developed on the inner bones of the mouth, and with vertical successors. 

 Notochord persistent, the vertebrae never advancing beyond the annular stage. 

 Fin-rays robust, the majority well-spaced, articulated, and divided distally; fulcra 

 large; dorsal fin not extending more than half the length of the trunk. Scales 

 rhombic, except occasionally in the caudal region." (A. S. Woodward, I. c, Pt. 

 Ill, p. 49). 



Genus Lepidotus Agassiz. 



" Trunk fusiform and only moderately compressed. Marginal teeth robust, 

 styliform, inner teeth stouter, often tritoral but smooth; opercular apparatus 

 well-developed, with a narrow arched pre-operculum, but with few branchiostegal 

 rays, and the gular plate wanting. Ribs ossified. Fin-fulcra very large, present 

 on all the fins, biserial. Paired fins small; dorsal and anal fins short and deep, the 

 former opposed to the space between the latter and the pelvic fins; caudal fin 

 slightly forked. Scales very robust, smooth or feebly ornamented; flank-scales 

 not much deeper than broad, with their wide overlapped margin produced forwards 

 at the superior and inferior angles; scales of the ventral aspect nearly as deep as 

 broad; dorsal and ventral ridge-scales usually inconspicuous." (A. S. Woodward, 

 I. c, Pt. Ill, p. 77). 



4. Lepidotus laevis Agassiz. (Plate XLVIII, Fig. 1). 

 1837-44. Lepidotus Icevis L. Agassiz. 



Poiss. Foss., Vol. II, Pt. I, p. 254; pi. XXIXe, figs. 4-6. 

 (?) 1846. Lepidotus subundatus G. von Miinster (errore). 



Beitr. Petrefakt., Pt. VII, p. 37; pi. Ill, fig. 16. 



