DIPTEEID-E. 
241 
■\ / 
I : 15 Dipterus keyserlingii, C. II. Pander, Ctenodipt. devon. Syst. 
pp. 22, 25 (P pi. vii. fig. 1). 
I t . Dipterus serratus, E. yon Eichwald, Leth. Rossica, vol. i. p. 1555. 
TV o'-;. Dental plate. 
'e.ital plate with numerous radiating ridges; tuberculations 
i. ti v al: compressed, almost imbricated, the pointed apices being 
irclied outwards. 
A Too. Devonian: St. Petersburg, Russia. 
*3 . imperfect dental plate. Enniskillen Coll. 
Dipterus (?) marginalis (Agassiz). 
-5, Ctenodus marginalis , L. Agassiz, Poiss. Foss. V. G, R. p. 123, 
pi. xxviii. a. fig. 21 ( non fig. 22) h 
■ S. Dipterus marginalis , C. H. Pander, Ctenodipt. devon. Syst. p. 24, 
pi. v. figs. 10-14, pi. vii. figs. 6, 7. 
Dipterus marginalis , E, von Eichwald, Leth. Rossica, vol. i. 
p. 1-737. 
/ ge. Dental plate. 
nailer species than D. keyserlingii, with the dental tubercula- 
■ h r- 1 ess compressed, less imbricating, and more obtusely pointed ; 
o\e mn.rgin and angle of the dental plate somewhat expanded, with 
• • • ght oncentric folds. 
.For/ 1 ?. df Log. Devonian: St. Petersburg. 
757 Imperfect dental plate. Ejtrton Coll. 
> • 
Dipterus (?) radiatus (Eichwald). 
>44. Ctenodus radiatus , E, von Eichwald, Bull Soc. Imp. Nat. Moscou : 
vol. xvii. p. 827. 
1845 Ctenodus iCoerthii, L. Agassiz, Poiss. Foss. V, G. R. p. 123, 
pi. xxxiii. fig. 36. 
It 58- Dipterus radiatus , C. H. Pander, Ctenodipt. devon. Syst. p. 22, 
ph vii. figs. 8, 9. 
18 >0. Dipterus radiatus , E. von Eichwald, Leth, Rossica, vol. i. p. 1536. 
T ip Dental plate. 
T en tuberculations somewhat laterally compressed, well sepa-* 
usely pointed, and slightly inclined outwards. 
j' ri.dfLoc. Devonian: St. Petersburg. 
7594. Dental plate ; Ischora. Purchased, 1845. 
1 This figure is named “ Ctenodus asteriscus, Ag.,” by G. G. Giebel, Fauna dar 
. /ell, Pisclm C-848), p. 313. 
K 
