128 OLD RED SANDSTONE FISHES. 



the genus Bothriolepis {see p. 110). The close affinity of B. hydrophila to B. Cana- 

 densis may be at once seen on comparing - the restored figures which I have given 

 of each (pp. 112 and 125). 



Geological Position and Localities. — From the Scottisli Upper Old Red Sand- 

 stone. Unless Fleming's isolated plate from Clashbennie (PI. XXX, Fig. 3) 

 belongs to the same species, the only known locality for Bothriolepis hydrophila 

 is Dura Den, in Fifeshire, where, like the Holoptychius Flemingii, it has occurred 

 in large numbers, closely packed together, one slab in the Royal Scottish Museum, 

 measuring nineteen by eleven inches, containing no less than twenty examples, 

 complete and incomplete. It would seem, however, that the Bothriolepis bed is not 

 the same as that in which the remarkable shoal of Holoptychii lies entombed, but 

 according to Dr. Anderson is "about fifty feet above the Holoptychius bed, which 

 lies in the bottom of the ravine, and level with the rivulet which traverses it " 

 ('Dura Den,' p. 52). 



Bothriolepis MAenouEniALA, Egerton, sp. Plate XXX, figs. 4, 5, 0. 



1862. Pterichthys macrocephalus, Egerton, sp. Quart. Jouru. Geol. Soc, vol. 



xviii, p. 103, pi. iii, figs. 7 — 9, 

 text-figs. 1 — 3. 

 1888. Bothriolepis li. H. Traquair. Geol. Mag. (3), vol. v, 



p. 510, and Ann. and Mag. Nat. 

 Hist. (6), vol. ii, p. 501. 

 1891. macrocephala, A. 8. Woodward. Cat. Foss. Fishes Brit. 



Mus., pt. ii, p. 231. 



Specific Characters, — Length not much over one inch; head large, measuring 

 about two thirds the length of the dorsal surface of the body carapace; dorsal 

 aspect of the body broad, ventral flat portion comparatively narrow ; median 

 ventral plate small; external surface of plates minutely pitted, reticulate ; outer 

 margin of proximal segment of arm distinctly serrated. 



Description. — The specimen represented in PL XXX, Fig. -1, shows the dorsal 

 surface with the head, but the last-named part looks almost like a ring, as the bone 

 is largely injured and lost over the central region. Nevertheless, we are struck 

 by the large size of the head, which shows a length equal to two thirds of that of 

 the body carapace. The sculpture of the plates of the body is lost. The right 

 pectoral appendage is shown, but in the drawing it has not been made long enough; 

 some evidence of the marginal denticulation is shown on the outer aspect of the 

 proximal portion (British Museum, P. 606). 



Fig. 5 shows the creature from the ventral aspect, and the narrow contour 



