MACROS EMIIDJE. 
179 
1854. Disticholepis fourneti , V. Thiolliere, Poiss. Foss. Bugey, pt. i. 
pi. viii. 
1878. Disticholepis fourneti, V. Thiolliere, ibid. pt. ii. p. 15. 
Type. Nearly complete fish; Lyons Museum. 
A large species attaining a length of about 0'3. Head with 
opercular apparatus longer than its maximum depth, and occupying 
about one-quarter of the total length of the fish; maximum depth 
of the trunk scarcely more than twice as great as the width of the 
caudal pedicle. Rays of dorsal fin about 34 in number, very stout, 
and denticulated on their posterior border; those of the hinder half 
of the fin somewhat expanded distally, and their length not ex¬ 
ceeding the depth of the caudal region of the trunk. Pelvic fins 
arising almost midway between the pectoral and caudal fins, and 
the anal arising shortly behind. Scales usually covered with fine 
striae extending from the delicate pectinations of the hinder border. 
This is the type species of the so-called Disticholepis, which is 
regarded by Wagner (Gelehrte Anzeig. k. bay. Akad. Wiss, 1860, 
p. 402) as doubtfully distinct from Macrosemius. 
It is not improbable that the fish from Cirin, erroneously ascribed 
by Thiolliere (op. cit. pt. ii. p. 14, pi. v. fig. 2) to Macrosemius 
rostratus , is a small example of this species. 
Form. Sf Loc. Lower Kimmeridgian (Lithographic Stone) : Ain, 
France. 
P. 4685. The greater portion of the trunk, with the dorsal and 
caudal fins, of a large individual chiefly shown in im¬ 
pression ; Cirin. Purchased, 1884. 
P. 4685 a. Imperfect impression of a fish 0*2 in length, showing 
all the fins; Cirin. Purchased , 1884. 
P. 1091. Hinder abdominal and caudal regions of a small indi¬ 
vidual, much fractured; Cirin. Distinct denticles' of 
ganoine are seen upon the posterior border of some of the 
hinder dorsal fin-rays. Egerton Coll. 
Macrosemius pectoralis, Sauvage. 
1883. Macrosemius pectoralis, H. E. Sauvage, Bull. Soc. Geol. France, 
[3] vol. xi. p. 477, pi. xii. fig. 17. 
Type. Nearly complete fish; counterpart in British Museum. 
A very small species, attaining a length of about G055. Head 
with opercular apparatus considerably longer than its maximum 
depth, and occupying about one-third of the length of the fish to 
the base of the caudal fin; caudal pedicle very slender, its width 
