180 
ACTINOPTERYGII. 
considerably less than one half the maximum depth of the abdo¬ 
minal region. Vertebral rings well ossified. Dorsal fin arising 
opposite the fourth or fifth vertebra, with about 26 rays, which are 
not expanded, but bifurcate distally at least in its hinder half. 
Pelvic fins arising midway between the pectoral and caudal fins, 
and the anal, with 6 or 7 rays, shortly behind. Squamation very 
thin. 
Form. Sf Loc. Portlandian: Meuse, France. 
P. 7359. Counterpart of type specimen; Upper Portlandian (“La 
Garde”), Savo'nnieres-en-Perthois, Meuse. The vertebral 
rings are shown to be complete and well ossified, and the 
neural arches throughout the trunk, the haemal arches 
in the caudal region, besides all the fin-supports, are 
especially robust. The present writer cannot distinguish 
more than 26 dorsal and 7 anal fin-rays. The hinder- 
most dorsal rays are clearly proved to bifurcate. Traces 
of the extremely delicate flank-scales occur above the 
pelvic fins. Purchased , 1894. 
Macrosemius andrewsi, A. S. Woodward. 
1895. Macrosemius andreivsi, A. S. Woodward, Geol. Mag. [4] vol. ii. 
p. 148, pi. vii. fig. 3. 
Type. Nearly complete fish; British Museum. 
A very small species, about 0’035 in length, closely similar to the 
preceding but with relatively stouter caudal region. Separate 
hypocentra and pleurocentra in notochordal sheath. Dorsal fin 
with about 25 slender rays, arising above the fifth pair of ribs. 
Pelvic fins arising about midway between the pectoral and caudal 
fins, and the anal, with 7 or 8 rays, shortly behind. Squamation 
very thin. 
Form. Loc. Purbeckian: Wiltshire. 
P. 6303. The type specimen, in counterpart, described and figured 
loc. cit.; Middle Purbeck, Teffont. 
Presented by Pev. W. 11. Andrews, 1890, 
The following specimens may perhaps indicate a species of Macro¬ 
semius from the Stonesfield Slate, while two premaxillse and a 
maxilla figured by J. Phillips (Geol. Oxford, 1871, p. 180, woodc. xl. 
figs. 8, 9) may pertain to the same fish; these specimens, however, 
are insufficient for determination. 
P. 3617. Dentigerous bone, probably maxilla, named Macrosemius 
brevirostris by Agassiz (Poiss. Foss. vol. ii. pt. ii. 1844, 
