47 
developed ; dorsal and anal fins small and short, the former at least in part 
opposed to the latter, though usually arising in advance of this. Scales of 
the flank in one [or three] deep series ; dorsal and ventral scales nearly 
equilateral ; ridge-scales absent. 
Ohs . — This interesting genus has hitherto been discovered only in the 
Keuper of Raibl, Carinthia,* and of Seefeld, in the Tyrol, f and it is some- 
what doubtful whether we are now justified in recording its occurrence in 
the Hawkeshury beds of New South Wales. In the Survey Collection, 
however, there is a small species, Avhich, so far as can he determined, only 
differs from the typical jPeltopleurus in the character added to the above 
definition in square brackets. It is perhaps contrary to analogy to permit 
such an extension of the genus ; hut, under any circumstances, the Ilawkes- 
bury fish is closely related to the European type just mentioned, and, awaiting 
further discoveries, it may he provisionally placed here. 
PeLTOPLEURUS (?) DEEIUS, sp. IIOV. 
PI. VI, Figs. 4, 5, 
Ohs . — Erom an extensive series of specimens, the following may he 
selected as characteristic and comparatively well preserved ; — 
(«) Type-specimen, wanting the pectoral fins, shown of the natural 
size in PI. VI, Pig. 4. 
{h) Imperfect fish, displaying the squamation, shown of twice the 
natural size in PI. VI, Pig. 5. 
(c) A smaller fish, aj)parcntly of more slender proportions. 
General Form . — Some examples of the fish are a little more elongated 
than others, but the differences seem to he mainly due to post-mortem 
distortion. The type-specimen probably displays the original proj)ortions, 
and in this the caudal pedicle is short and slender, and the maximum depth 
of the abdominal region is contained about three times in the total length of 
the fish. The head and opercular apparatus occupy considerably less than a 
quarter of the total length. The dorsal fin is somewhat larger than the anal, 
and arises just in advance of the latter. 
* P. splendens, R. Kner, Sitzungsb. math.-naturw. Cl. k. Akad. Wiss., 1866, Vol. liii, Pt. i, pp. 180-183, 
PI. iv, fig. 3. 
+ P. humilis, R. Kner, ihid., 1867, Vol. Ivi, Pt. i, p. 904, PI. 1, fig. 2. 
