276 
ACTIXOPTERYGII. 
divided distally. Pelvic fins present; dorsal and anal fins low and 
fringe-like, the former occupying the greater part of the back and 
the latter much shorter, arising more posteriorly ; caudal fin with 
slightly excavated hinder border. Scales covering the anterior part 
of the body in advance of the median fins. 
Pycnodus platessus (Blainville). 
1796. Coryphcena apoda, G. S. Volta, Ittiolit. Veronese, p. cxlvii. 
pi. xxxv. fig. 1. 
1818. Zeus platessus, H. D. de Blainville, Nouv. Diet. d’Hist. Vat. 
vol. xxvii. p. 356. 
1833-44. Pycnodus p)hitessus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 
p. 17, pt. ii. p. 185, pi. lxxii. figs. 1, 2 ( non figs. 3, 4). 
1856. Pycnodus platessus, J. J. Heckel, Denkschr. k. Akad. Wiss., 
math.-naturw. Cl. vol. xi. pp. 204, 226, pi. viii. figs. 5, 7. 
r lAs/'. . 
Type. Nearly complete fish Paris Museum of Natural History. 
The type species, attaining a length of about 0*3. Maximum 
depth of trunk equalling half the length of the fish exclusive of 
the caudal fin ; head with opercular apparatus occupying about 
one-quarter of the total length. Teeth of the splenial hone smooth, 
the outermost indented ; the inner or principal series equalling in 
breadth the two flanking series, of which the inner comprises teeth 
broader than long, the outer nearly round teeth. Dorsal fin 
occupying somewhat less than three-quarters of the total length of 
the back, arising almost at the highest point. 
Form. Sf Loc. Upper Eocene : N. Italy. 
38000. Plaster cast of type specimen ; Monte Bolca, near Verona. 
Purchased, 1864. 
41083. Imperfect specimen, wanting extremity of caudal region, 
displaying the right splenial dentition; Monte Bolca. 
Purchased , 1868. 
Pycnodus gibbus, Agassiz. 
1796. Coryphcena apoda, var., G. S. Volta, Ittiolit. Veronese, p. cxlvii, 
pi. xxxv. fig. 2. 
1796. Diodon reticulatus, G. S. Volta, ibid. p. xciv, pi. xx. fig. 3. 
1844. Pycnodus gibbus = Pycnodus platessus, L. Agassiz, Poiss. Foss. 
vol. ii. pt. ii. p. 185, pi. lxxii. figs. 3, 4. 
1856. Pycnodus gibbus. J. J. Heckel, Denkschr. k. Akad. Wiss., math.- 
naturw. Cl. vol. xi. p. 226, pi. viii. figs. 3, 4, 6. 
Type. Nearly complete fish. , A Ac « - / - 
A small species, attaining a length of about O’lo. Maximum 
depth of trunk slightly exceeding half the total length of the fish 
