CEOSSOPTFEYGUI. 
378 
28863. Remains of fish, 0-27 in length, ventral aspect. 
Purchased , 1854. 
P. 827, P. 3293. Crushed trunk of fish, wanting head and paired 
fins. Egerton 4' Enniskillen Colls. 
P. 827 a, P. 3293 a. Portions of head and anterior scales of a large 
individual: a close uniform series of conical teeth is seen 
in the mandible. Egerton 4' Enniskillen Colls. 
Under the preoccupied generic name of Gyrolepis, and with the 
specific name of G. posnaniensis, scales much resembling those of 
the foregoing genera, from Lower Palaeozoic boulders near Meseritz, 
Silesia, are described by G. Xade, Programm k. Realschule zu 
Meseritz, 1858, pp. 17, 18, figs. 8-10. 
Genus MEGALICHTHYS, Agassiz. 
[Poiss. Loss. vol. ii. pt. ii. 1844, pp. 89, 154.] 
f Syn. Centrodus, F. M‘Coy, Arm. Mag. Nat. Hist. [2] vol. ii. 1848, p. 3, 
and ibid. vol. iii. 1849, p. 140. 
/ 6 * t 
jS (&lr\ p. 67. 
Parabcitrachus, R. Owen, Quart. Journ. Geol. Soc. vol. ix. 1853, 
p. 67. 
^^ ^Rhomboptychins, J. Young (ex Huxley, MS.), Quart. Journ. Geol. 
o* Soc. vol. xxii. 1866, p. 604. 
Ganolodus, R. Owen, Trans. Odontol. Soc. vol. v. 1867, p. 354 
(in part). 
Ectosteorliachis, E. D. Cope, Proc. Arner. Phil. Soc. vol. xix. 
1880, p. 56. 
Cranial roof-bones in advance of the parietals rarely fused into a 
continuous shield, without a median frontal foramen ; an anterior 
azygous jugular plate present. Teeth rounded in transverse section. 
Ossified vertebrae in the form of narrow rings. First dorsal fin 
nearly opposite to the pelvic pair, and the second dorsal opposed to 
the anal. Tail intermediate between the diphycercal and hetero- 
cercal stages. Scales more or less smooth and punctate. 
> 
Megalichthys hibberti, Agassiz. 
[Plate XIII. fig. 4.] 
1835. Ichthyolithus clackmannensis, J. Fleming, Eclinb. New Phil. 
Mag. vol. xix. p. 314, pi. iv\ figs. 1-3. [Portions of Fish : Edin¬ 
burgh Museum.] 
1844. Megalichthys hibberti, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. 
p. 90, pis. lxiii., lxiii. a., lxiv. 
