BOTHRIOLEPIS MAJOR. 117 



left side, not so complete, is seen in Fig. 5 (also from a cast), but here we have the 

 greater portion of the upper arm attached, while in PI. XXIII, Fig. 7, we have a 

 natural size representation of the same element broken, it is true, along its inner 

 and posterior margins, but showing the brachial process (b. p.) in its entirety. This 

 last figure, which is taken from an actual specimen from Whitemire, near Forres, 

 shows also in an unmistakable way the stellation of the bases of the confluent 

 tubercles. 



PI. XXV, Fig. 6, represents the left posterior ventro-lateral plate, one half 

 natural size, from a cast. It is nearly complete, and shows both the horizontal or 

 ventral and the ascending or lateral portions, the considerable height of the latter 

 being interesting in connection with the large size of the area on the posterior 

 dorso-lateral, which it overlaps. 



The lozenge-shaped median ventral is shown in PI. XXIV, Fig. 5, which is also 

 taken from a cast, one half natural size. In general configuration it presents no 

 features specially distinguishing it in form from the corresponding plate in 

 Pterichthys or in Asterolepis. 



Pectoral Appendages. — In no case has an entire "arm" of Bothriolepis major 

 been found, though in PI. XXV, Fig. 5, we have a view of the greater part of the 

 ventral aspect of the proximal segment, the elements here seen being the ventral 

 articular, part of the ventral anconeal and part of the external marginal. The two 

 articular pieces, dorsal and ventral, seem to have much the same general shape, so 

 that I feel unable to say to which category the detached specimens represented in 

 PL XXVI, Figs. 2 and 3, respectively belong. Of these Fig. 2 shows the outer 

 sculptured surface, Fig. 3 the internal smooth aspect of a similar plate. The 

 appended text figures show the internal and external aspects of the upper extremity 

 of an arm from Scat Craig. On the outer aspect, Fig. 60, the articular dorsal 

 [d. ar.) and ventral (v. ar.) plates are seen to be in contact for a considerable 

 distance above the space occupied by the external marginal, while on the inner, 

 Fig. 61, the internal articular (i. ar.) is displayed with its narrow upper margin 

 taking part in bounding the opening by which these plates clasp the base of the 

 brachial porcess (b.p.). 



Of the " forearm," with the exception of the one figured by Agassiz as 

 Placothorax paradoxus, ' Poiss. Foss. v. gres rouge,' PI. XXX a, Figs. 22, 23, 1 have 

 only seen the impression of a portion deficient at both ends, of which a plaster 

 cast of one half the natural size is represented in PI. XXVI, Fig. 4. 



Entire Specimens. — It is only in the uppermost or " Rosebrae " beds of the 

 Upper Old Red Sandstone of the Elgin district that one or two specimens with body 

 plates in apposition have been found — impressions I should say, for in the Rosebrae 

 rock not a vestige of the osseous substance remains in any of its contained fish- 

 bones, plates, or scales. The best of these which I have seen is from Rosebrae 



