from Achanarras Quarry^ Caithness. 483 



D. striahis. Mr. Smith Woodward has suice pointed out to 

 me that in one specimen of longispiaus 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^ -^Sv cornutus, Ag., latus, Ag., and quad- 

 ratus, 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 " 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. Glyptolejns paucidens (Ag.). — liemains 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. leptoiiterus , 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 macrolepidoius^ Ag. — In my paper on the 



