PYCNODOXTIDiE. 
225 
without caudal fin; rostrum prominent, and head with opercular 
apparatus occupying somewhat less than one-quarter of the total 
length of the fish. Vertebral axis at origin of dorsal fin midway 
between the dorsal and ventral borders of the fish. Principal 
series of mandibular teeth much wider than the two outer series, of 
which the innermost is insignificant. Dorsal fin occupying con¬ 
siderably more than half of the back, much more elevated than the 
anal fin, which is also shorter. Ridge-scales delicate on the back, 
robust but feebly serrated on the ventral border; flank-scales 
ornamented with delicate radiating rugae. 
Form. Sf Log. Lower Kimmeridgian (Lithographic Stone): Ain, 
Prance, and (?) Bavaria. 
P. 1635. A typical specimen in counterpart, much disturbed ; Girin, 
Ain. Eger ton Coll. 
P. 4693. Imperfect trunk ; Girin. 
Purchased, 1884. 
49132. Plaster cast of a small fish, probably of this species; Kel- 
heim, Bavaria. Purchased , 1878. 
Microdon wagneri (Thiolliere). 
1854. Pycnodiis wagneri, V. Thiolliere, Poiss. Foss. Bugey, pt. i. p. 23, 
with figure. 
1856. Microdon wagneri, J. J. Heckel, Denkschr. k. Akad. Wiss., 
math.-naturw. Cl. vol. xi. p. 201. 
1860. Microdon waqneri, A. Wagner, Gelekrte Anzeig. k. bay. Akad, 
Wiss. vol. 1. p. 396. 
Type. Nearly complete fish; Lyons Museum. 
A species resembling the type in size, general form, and pro¬ 
portions, and apparently only differing in the extension of the 
squamation over the middle of the flank of the anterior half of 
the caudal region. 
Form. Sf Loc. Lower Kimmeridgian (Lithographic Stone): Ain, 
France. 
P. 1636. A fine specimen 025 in length preserved in impression 
and wanting the rostral portion of the skull; Girin. The 
ribs of the scales originally on the flanks of the caudal 
region are indicated ; and the form of the hinder part of 
the trunk suggests that the figured type specimen has 
been somewhat distorted by crushing in that region. 
Egerton Coll. 
Q 
PAET III. 
