374 
CTtOSSOPTEKVGir. 
second, the latter deeper than long and similar to the opposing anal. 
Scales of moderate size. 
Form. Sf Log. Lower Old Red Sandstone : Caithness. 
34990, 41359. Large specimen, in counterpart, showing the head 
and abdominal region from above, and the tail from the 
lateral aspect; Thurso. Many of the bones of the head 
are distinct and appear as in Osteolepis and Diplopterus. 
Purchased> 1860, 1869. 
42462. Small, imperfectly preserved fish, wanting head; Sandside, 
Reay. Peach Coll. 
42410-11, 42450, 42458-59, 42461, 42463-64, 42466. Seven 
small fishes and the caudal region of two others, of the 
form doubtfully assigned to this species by R. H. Traquair. 
Geol. Mag. [3] vol. v. p. 516 ; South Head, Wick. 
Peach Coll. 
42437, 42439. Somewhat larger imperfect specimen, in counterpart; 
South Head. Peach Coll. 
Tlrarsius pholidotus, Traquair. 
[Plate XIII. figs. 2, 3.] 
1888. Thursius pholidotus, R. H. Traquair, Geol. Mag. [3] vol. v. 
p. 516. 
Type. Imperfect fish ; Edinburgh Museum. 
A species attaining a somewhat larger size than the type, and 
distinguished by the relatively very large proportions of the scales, 
and the comparative shortness and stoutness of the jaws. 
Form. Sf Loc. Lower Old Red Sandstone : Caithness. 
33173. Impression of head and opercular apparatus, and anterior 
scales ; Holburn Head, near Thurso. Purchased , 1857. 
41361. Imperfect head and trunk, 0 - 22 in length, wanting the 
pectoral fins. The hinder half of the fossil is drawn, of 
the natural size, in PI. XIII. fig. 2, and the fins are indi¬ 
cated by the lettering ; the head and abdominal region 
are much crushed and broken, and the former is exposed 
from beneath. Purchased , 1869. 
49664. Much crushed and broken individual, 0*19 in length, in 
counterpart, showing portions of the fins ; Holburn Head. 
