40 
POSTSCRIPT ON DEVONIAN ICHTHYOLITES. 
that our arguments and reasoning employed two and three years ago, have been prodigiously strengthened by the 
additional light thrown upon many new types of true Devonian age. Thus, besides the numerous species of fishes 
of the Old Red Sandstone already spoken of (p. 64), and the new genera and species found on the Slavenka, we 
learn from M. Agassiz, that we had really obtained from the red sandstone ot the Andoma (p. 48), the Pterichthys 
major (Ag.), a species previously named from a specimen found on the banks of the Findhorn, near Elgin. This, 
it is important to remark, is the first representative of the family of the Ccphalaspides found in Russia. In addition 
to the forms of teeth of Dendrodus alluded to (pp. 52 and 6(>) as occurring near Riga (and which have recently been 
sent from Cremon in Livonia by our distinguished friend the Baron H. de Meyendorf), M. Agassiz announces the 
presence of Dendrodus latus (Owen), and Lamnodus Panderi or hastalus (Ag.) ( Dendrodus hastatus, Owen), both of 
them published Scottish species, whilst Professor OweD, examining the structure of the teeth with the microscope, 
has named another Russian ichthyolite, Dendrodus Murchisoni, showing how it is distinguished from the Scottish 
species D. biporcatus (see Appendix B. and Plate B,). The fossil which M. Agassiz had named Glyptostevs fa- 
vosus (see p. 4f>), is, it appears, accompanied by another species of the same genus that, we had named G. retie u- 
lutus, which is the same as M. Eichwald’s Bofhriolepis ornata. These last-mentioned ichthyolites appear not only 
on the banks of the Priksha (erroneously spelt Priutchka in our next chapter), in the A 7 aldai Hills, and at Tchudova, 
but also on the Siass and Andoma rivers, in the north-eastern range of the Devonian rocks. One of them occurs 
at Kipet, near Bielef (p. 58), in the great central Devonian dome (see section beneath the Map, PI. VI.). Both 
these species of Glyptosteus, or Bothriolepis, so widely diffused in Russia, are common to the north of Scotland ; 
the first-mentioned being found in Perthshire (C'lashbennie) and Elginshire, the last in Nairn, Elgin and Murray 
shires. Not only is the smaller species of Chelonichthys, C. minor (Ag.), ( Asterolepis , Eichw. 1 ), found both in 
Scotland and at Riga; but we now learn that the Scottish locality of Elgin also contains fragments of the Russian 
monstei C. Asmusii ! Lastly, we may state, that in confirming our view of the identity of the Devonian rocks of 
the dome-shaped region around Orel, \ oroneje and Bielef with those of the Baltic and North-eastern govern- 
ments, M. Agassiz assures us that certain hones from all these tracts, and which he has not yet described, belong 
to the same species. 
The results of the close and careful comparison of M. Agassiz are truly remarkable in sustaining our views of the 
great uniformity of the paleozoic deposits over Very wide areas of Europe, and in showing the necessity of con- 
sidering the Devonian or Old Red group a separate system. The reader will, indeed, see, that instead of eight or 
ten species of the Devonian fossil fishes of Scotland and Russia being identical, as we have printed it in the next 
chapter, that number is already more than doubled ; or, in other words, of the known Russian ichthyolites pecu- 
l iar to this age, two-thirds are specifically the same as those of the same epoch in Great Britain ! 
1 Though we have now learned that M. Eichwald used the word Asterolepis in reference to the gigantic ichthy- 
olite of Diirpat, before M. Agassiz had named it, we adhere in this volume to the word Chelonichthys, simply 
because we have long used it in print, as derived from the great authority of Neufchatel. If, according to the un- 
derstood custom of accepting the first name (which ought, however, to depend upon the object having been figured 
and described), the name of Asterolepis be finally adopted, we have in the meantime simply endeavoured to pre- 
serve in this chapter and in the Table attached to the Map, a coincidence with the text (Chap. IV.) which we printed 
two years ago. — April, 1845. (For all palaeontological details, see Appendix and vol. ii.) The Russian Palaeozoic 
corals are described by Mr. Lonsdale in the first part (or A.) of the Appendix to this volume ; and a new species of 
Dendrodus is described by Professor Owen (B. of Appendix) from a microscopic examination of the teeth of that 
genus. 
