﻿DIl'TERIDJS. 24:1 



1858. Dlpterus keyserlingii, C. II. Pander, Ctenodipt. devon. Syst. 



pp. 22,25 (Ppl. vii. fig. 1). 

 r860. Dlpterus serratus, E, von Eichwald, Leth. Rossica, vol. i. p. 1633. 



Type. Dental plate. 



Dental plate with numerous radiating ridges ; tuberculations 

 laterally compressed, almost imbricated, the pointed apices being 

 inclined outwards. 



Form. S,- Loc. Devonian : St. Petersburg, Russia. 



P. 3375. Imperfect dental plate. Enniskillen Coll. 



Dipterus (?) marginalis (Agassiz). 



1845. Ctenodus marginalis, L. Agassiz, Poiss. Foss. V. G. R. p. 123, 



pi. xxviii. a. fig. 21 (non fig. 22) \ 

 1858. Dipterus marginalis, C. H. Pander, Ctenodipt. devon. Syst. p. 24, 



pi. v. figs. 10-14, pi. vii. figs. 6, 7. 

 18G0. Dipterus marginalis, E. von Eichwald, Leth. Rossica, vol. i. 



p. 1537. 



Type. Dental plate. 



A smaller species than D. Jceyserlingii,, with the dental tubercula- 

 tions less compressed, less imbricating, and more obtusely pointed ; 

 one margin and angle of the dental plate somewhat expanded, with 

 slight concentric folds. 



Form. 6f Loc. Devonian : St. Petersburg. 



P. 757. Imperfect dental plate. Egerton Coll. 



Dipterus (?) radiatus (Eichwald). 



1844. Ctenodus radiatus, E, von Eichwald, Bull. Soc. Imp. Nat. Moscou, 

 vol. xvii. p. 827. 



1845. Ctenodus tcoerthii, L. Agassiz, Poiss. Foss. V, GL R. p. 123, 

 pi. xxxiii. fig. 36. 



1858. Dipterus radiatus, C. H. Pander, Ctenodipt. devon. Syst. p. 22, 



pi. vii. figs. 8, 9. 

 1860. Dipterus radiatus, E. von Eichwald, Leth. Rossica, vol. i. p. 1536. 



Type. Dental plate. 



Dental tuberculations somewhat laterally compressed, well sepa- 

 rated, obtusely pointed, and slightly inclined outwards. 

 Form. Sf Loc. Devonian : St. Petersburg. 



19594. Dental plate; Ischora. Purchased, 1845. 



1 This figure is named " Ctenodus asteriscus, Ag.," by G. G-. G-iebel, Fauna- der 

 Torwelt, Fische (1848), p. 343. 



PAET II. B 



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