114 OLD RED SANDSTONE FISHES. 



like bodies extending along the dorsal margin of the heterocercal caudal fin, and 

 another row, much less extensive, placed just below the tip of that fin. To afford 

 a clearer idea of the contour of the parts concerned I reproduce one of Professor 

 Patten's figures, which shows not merely one, but two dorsal fins. The second of 

 these, very prominent, is obviously the equivalent of the one present in Pterichthys, 

 while the other, in front, is more undefined. 



Professor Patten's paper contains also some interesting details concerning the 

 mouth- and eye-plates, the consideration of which must be deferred. 



Geological Distribution. — Bothriolepis is the characteristic Asterolepid genus of 

 the estuarine aspect of the Upper Devonian formation, and is represented by 

 various species in strata of that age in Britain, Russia, Canada, and the United 

 States. 



Bothriolepis major, Agassiz, sp. Plates XXIII — XXVI. 



1844. Glyptostetts reticulatus, Agassiz. Poiss. Foss., vol. i, p. xxxiv (name only). 



— Pterichthys major, Agassiz. Poiss. Foss. v. Gres. rouge, pp. 5, 19, 133, 



pi. xxxi, figs. 1 — 3. 



1845. Bothriolepis ornatus, Agassiz (errore). Ibid., pi. xxix, figs. 3 — 5. 



— Placothorax paradoxus, Agassiz. Ibid., p. 134, pi. xxxa, figs. 20 — 23. 

 1860. Asterolepis major, Eichwald. Leth. Eossica, vol. i, p. 1511. 



1880. Bothriolepis major, Lahusen. Verb, russ.-kais. miner. Gesellsch. [2], 



vol. xv, p. 136. 

 1888. B. H. Traguair. Geol. Mag. (3), vol. v. p. 510, and 



Ann. Mag. Nat. Hist. (6), 



vol. ii, p. 501. 



giganteus, B. H. Traguair. Geol. Mag. (3), vol. v, p. 510, 



and Ann. Mag. Nat. Hist. (6), vol. ii, 



p. 504, pi. xviii, fig. 3. 



1891. major, A. S. Woodward. Cat. Foss. Fishes Brit. Mus., 



pt. ii, p. 226, pi. vi, figs. 5—8. 

 1896. — B. H. Traguair. In Harvie-Brown and Buckley's 



Vert. Fauna Moray Basin, p. 265, pi. viii. 



Specific Characters. — Median dorsal plates not carinated mesially ; sensory 

 groove crossing pre-median plate tolerably close to the anterior margin ; sculpture 

 consisting of tubercles more or less confluent into reticulating ridges ; tubercles 

 showing stellation of bases in unworn specimens; no prominent denticulation 

 observed on margins of pectoral appendages. 



Description. — The photographic figures given in PI. XXIII — XXVI will 

 give the reader a better idea of the form and sculpture of the bony elements 

 forming the exoskeleton of this species than pages of words; the following 



