66 
ACTINOPTERYGII. 
large, extended forwards as short, acute ridges ; anterior half of the 
scale smooth or marked with finer transverse ridges. 
Form. Sf Loc. Upper Triassic (Lettenkohl) : Wiirtemberg. 
P. 7402. Two fragments of dolomite with scales and a thin tuber- 
cnlated hone ; Combnrg, near Hall. One scale is smooth 
n its anterior half. Purchased. 
Genus PRISTISOMUS, A. S. Woodward. 
[Foss. Fishes Hawkesbury Series, Gosford (Mem. Geol. Surv. 
N. S. Wales, Palseont. no. 4, 1890), p. 32.] 
Trunk deeply fusiform. Marginal teeth large, styliform, and in 
close series. Fin-fulcra small. Paired fins moderately developed ; 
dorsal and anal fins remote, not much extended, the former partly 
opposed to the latter ; caudal fin robust, scarcely forked. Three or 
more series of the flank-scales vertically elongated; dorsal and 
ventral scales as broad as deep; a dorsal and ventral series of 
prominent, acuminate ridge-scales. 
Pristisonms gracilis,, A. S. Woodward. 
1890. Pristisomus gracilis, A. S. Woodward, op. cit. p. 33, pi. v. fig. 1, 
pi. vi. fig. 1, pi. viii. fig. 1. 
Type. Nearly complete fish ; Geol. Survey Museum, Sydney. 
The type species, attaining a length of about 0’12. Head with 
opercular apparatus occupying about one-quarter of the total length; 
trunk gracefully fusiform, the maximum depth contained more than 
two-and-a-half times in the total length of the fish. Dorsal and 
anal fins almost of equal size, much elevated, and with a relatively 
short base-line. 
Form. § Loc. Lower Hawkesbury-Wianamatta Series (Upper 
Trias) : Gosford, New South Wales. 
P. 6275. Fish wanting paired fins. By exchange , 1890. 
P. 6277. Slab showing another specimen associated with P. crassus. 
By exchange , 1890. 
Pristisonms latus, A. S. Woodward. 
1890. Pristiso?nus latus , A. S. Woodward, op. cit. p. 35, pi. v. figs. 2-4. 
Type. Nearly complete fish; Geol. Survey Museum, Sydney. 
A slightly larger species than the type, with somewhat deeper 
