376 
CEOSSOPTERYGII. 
1 848. Gyroptychius diplopteroides, F. M‘Coy, ibid. p. 309. [Wood- 
wardian Museum.] 
1849. Diplopterus , H. Miller, Footprints of the Creator, p. 57, woodc. 
figs. 16, 17. 
1855. Diplopterax affinis and D. agassizii, F. M'Coy, Brit. Pakeoz. Foss, 
p. 586. 
1855. Diplopterax gracilis, F„ M‘Coy, ibid. p. 586, pi. ii. c. fig. 1. 
1855. Diplopterax macrolepidoius, F. M‘Coy, ibid. p. 587 (in part). 
1855. Gyroptychius diplopteroides , F. M‘Coy, ibid. p. 597, pi. ii. c. fig. 3. 
1860. Diplopterax borealis , C. H. Pander, Saurodipt., Dendrodont. &c. 
devon. Syst. p. 23, pi. iii. figs. 22-27, pi. iv. 
1888. Diplopterus agassizii, R. H. Traquair, Geol. Mag. [3] vol. v. 
p. 516. 
1890. Diplopterus agassizii, R. H. Traquair, Ann. Mag. Nat. Hist. [6] 
vo^. vi. p. 484, woodc. fig. 3. 
Type. Imperfect fish ; o&rrr T. S. 
The type species, attaining a large size, sometimes measuring 0*5 
in length. Head with opercular apparatus occupying somewhat 
less than one quarter of the total length; operculum deeper than 
broad, suboperculum smaller and broader than deep. Pelvic fins 
situated far behind the middle point of the fish; first dorsal fin 
much smaller than the second, the latter deeper than long and 
similar in all respects to the opposing anal; caudal fin obtusely 
pointed posteriorly, the origin of its upper lobe precisely opposite to 
that of the lower, and the distance from this point to the origin of 
the first dorsal greater than the total length of the fin. Scales 
relatively large. 
Form. Sf Log. Lower Old Red Sandstone : Orkney, Caithness, 
Nairnshire, and Banffshire h 
(i.) Orkney (typical D. agassizi). » 
P. 183. Large well-preserved specimen, in counterpart, 0*42 in 
length, wanting the dorsal fins and showing only portions 
of the pelvics and anal. Purchased , 1881. 
P. 32S4-a,. Two smaller specimens, showing portions of all the 
fins ; Belyacreugh. Enniskillen Coll. 
29252 a. Fish 0*29 in length, displaying the fins, but with imper¬ 
fect head. Purchased. 
P 821. Fronto-ethmoidal portion of cranial shield. Ec/erton Coll , 
1 The so-called Diplopterus macrocephalus is also supposed to be represented 
by fragments from the Russian Devonian by L. Agassiz, Poiss. Foss. V. G. R. 
(1845), p. 138, pi. xxxi. a. figs. 1-7, and E. von Eichwald, Letb. Rossica, 
vol, i. (i860), p. 1556, pi. lvi. fig. 5. 
) 
yyw 
Traill Collection. ^ ^ ^ 
