526 
ACTINOPTERYGrII. 
Scales of moderate size, the exposed area rhombic in shape, orna¬ 
mented with numerous closely arranged elongated tubercles, in hori¬ 
zontally directed parallel series. 
Form. Sf Loc. Upper Hawkesbury-Wianamatta Series : Talbralgar, 
New South Wales. 
Not represented in the Collection. 
Genus MOlLUIlUSj Traquair. 
[Trans. Roy. Soc. Edinb. vol. xxx. 1881, p. 43.] 
Trunk robust. Mandibular suspensorium oblique ; teeth small 
and conical. Ein-rays simple, not branching, but merely attenuated 
distally; fulcra minute or absent. Dorsal fin rounded, elongated, 
arising in advance of the somewhat shorter anal ; caudal fin 
obliquely truncated posteriorly, not forked. Scales sculptured; a 
prominent series of ridge-scales between the occiput and the dorsal 
fin. 
Holurus park!, Traquair. 
1881. Holurus parki, R. H. Traquair, Trans. Roy. Soc. Edinb. vol. xxx. 
p. 44, pi. iii. figs. 9-12. 
Type. Imperfect fish ; Geological Survey of Scotland. 
The type species, attaining a maximum length of about 0*1. 
Maximum depth of trunk contained about three and a half times in 
the total length. Head and opercular apparatus occupying about 
one quarter of the total length ; external bones ornamented with 
fine strise, sometimes interrupted. Scales of the abdominal region 
and the anterior portion of the caudal region finely striated, a few 
of the strise concentric with the margins, but the majority oblique 
and some terminating in denticulations of the hinder border; ridge- 
scales finely striated. 
Form. Sf Loc. Calciferous Sandstones (Cement-stone Group) : 
Eskdale, Dumfriesshire. 
P. 4055. Imperfect head and abdominal region. 
.» Purchased, 1883. 
P. 5982. Imperfect fish, wanting part of the head and upper caudal 
lobe. Purchased , 1889. 
Two doubtful species from the Calciferous Sandstones are also 
named Holurus fulcratus (Traquair, loc. cit. p. 46, pi. iii. figs. 13. 
14) and H. iscTiypterus (ibid. p. 66, pi. iii. figs. 15, 16), the former 
from Eskdale and the latter from Coldstream Bridge. The first is 
