122 OLD RED SANDSTONE FISHES. 



and having the outer margin placed upwards. It is to be noted that this outer 

 margin displays a row of stout denticles like those in B. caviadensis, etc. 



In Fig. G we have a plaster mould of a fragment of a head, showing a large 

 portion of the median occipital, and nearly the whole of the post-median plate. The 

 former plate seems to differ from the corresponding one in B. major, by having the 

 posteriorly directed apex of the V-shaped sensory groove somewhat farther forward. 



Ttemarlcs. — In looking back on the rather fragmentary material which I have 

 brought together under the term Bothriolepis obesa, it is difficult to clear one's 

 mind altogether of a doubt as to whether more than one species may not be here 

 included. In other words, might not possibly the Harelaw specimens (PI. XXVII, 

 Figs. 8 — 6) be different in that respect from the others which are from the neigh- 

 bourhood of Jedburgh ? It is, however, difficult to formulate unmistakable evidence 

 of such a view, so I consider it better to keep the specimens together under one 

 name until further material is forthcoming. Meanwhile, taking everything into 

 account, we have here a form distinguished from 7>. major by the obvious carina- 

 tion of the anterior median dorsal plate (the posterior one is not yet in evidence), 

 the short and deep aspect of the lateral plates, and, if the samples from Harelaw 

 belong to the same species, also by the prominent serration of the outer aspect, 

 of the external marginal plate of the pectoral appendage. Further material 

 is much to be desired, as I have seen no specimens save the few which are pre- 

 served in the Natural History Department of the Royal Scottish Museum, and in 

 the Collection of the Geological Survey of Scotland. These were, I understand, 

 all obtained from quarries which have not been worked for many years. 



Geological Position ami Localities. — The specimens represented on PI. XXVIII, 

 Pigs. 2—4, and on PI. XXVII, Fig. 2, are from Rule Water, Jedburgh, Roxburgh- 

 shire; those seen in PI. XXVII, Fig. 1, and in PI. XXVIII, Figs. 1 and 5, are 

 also from the neighbourhood of that town, though the precise locality is not 

 known, while Figs. 3, 4, 5, and 6 on PL XXVII are taken from plaster moulds 

 of specimens from Harelaw, near Chirnside, in Berwickshire. 



BOTHRIOLEPIS LEPTOCHELRUS, Traquair. Plate XXIX. 



1869. Pteeichthys major, A. Geikie. Expl. of Sheet 14, G-eol. Survey of 



Scotland, pp. 12 and 13. 

 1882. — A. Geikie. Text-book of Geology, p. 716. 



1888. Bothriolepis major, 11. II. Traquair. Ann. and Mag. Nat. Hist. (6), 



vol. ii. p. 501. 

 1892. lkptocheirus, B. H. Traquair. Proc. Roy. Pliys. Soc. 



K.lm., vol. xi, p. 286. 



