483 
from Achanarras Quarry , Caithness. 
D. striatus. Mr. Smith Woodward lias since pointed out to 
me that in one specimen of longispinus from Gamrie, in the 
British Museum, a rudimentary second pectoral spine is 
present ; but, considering the small size of this projection 
from the pectoral arch and the difference in the shape and 
sculpture of the other spines, I do not yet see my way to 
retracting the genus. 
6. Pterichthys Milleri , Ag. — So far as I am aware no true 
Pterichthys has* hitherto been recorded from the Caithness 
beds, as the Pterichthys Dickii of C. W. Peach, from John o’ 
Groats, has been referred by me to another genus, Micro - 
brachius. But there can be no doubt as to the identity of 
the Achanarras specimens with the common Pterichthys of the 
Orkney and Moray-Firth beds, in which must also be included 
Pt . testudinarius y Ag., cornutus , Ag., latus y Ag., and quad - 
ratuSj Egert. 
7. Coccosteus decipiens , Ag.— Detached plates of this species 
are common in many other localities in Caithness ; but from 
no place in the whole of Scotland have I seen specimens 
which display the general configuration of the fish to better 
advantage. If a pectoral spine or 66 Ruderorgan ” existed in 
Coccosteus , such as Prof, von Koenen thinks may yet be 
found in Scotch specimens, surely it could not fail to be seen 
in those from Achanarras. But not even a suspicion of such 
an appendage can be detected. 
8. Homosteus Milleri , Traq. — A large but rather disturbed 
specimen of this from Achanarras is contained in the collec- 
tion of the Geological Survey of Scotland. 
9. Glyptolepis paucidens (Ag.). — Remains of this, the 
common Glyptolepis of the Caithness beds, are not uncommon 
in the quarry at Achanarras, one entire specimen in the 
Edinburgh Museum measuring 24 inches in length and 
having the acutely lobate pectorals beautifully displayed. 
There can be no doubt that this species is closely allied to 
the G. leptopterus , Ag., of the Moray-Firth beds ; but the 
laniary teeth of the latter, so far as I can ascertain, seem to 
be rounded in section up to nearly the tip, while those of G. 
paucidens become acutely trenchant very soon above their 
base. 
10. Osteolepis macrolepidotus ) Ag. — In my paper on the 
