166 
ACTING PTERre II. 
vacuity ; and fouT slender basals can be seen supporting 
the appended pectoral fin (pcf.). The vertebral centra are 
obscure, but their arches are distinct; the characteristic 
expansions of the neural arches in the abdominal region 
are especially well shown. The pelvic fins (plv.), with 
their closely apposed supporting bones, are preserved just 
in advance of the dorsal fin, which is opposed to the space 
between the pelvic pair and the anal. The rays of the 
dorsal fin, probably about 17 in number, are stouter than 
those of the anal, which seem to have been shorter and 
not less than 30 in number. Of the caudal fin, only a 
fragment remains. Leiuis Coll. 
P. 9168. Larger and more im'perfect specimen, shown of the natural 
size in PI. XII. fig. 2. The head is vertically crushed 
and seen apparently from above. The postorbital portion 
of the cranium is longer than broad, while the interorbital 
and rostral portions are very slender. The left mandibular 
ramus is sufficiently complete to indicate that the 
quadrate articulation was beneath the hinder border of 
the orbit. The operculum (ojj.) is trapezoidal in shape, 
and slightly crimped postero-superiorly ; an impression on 
the right suggests that the preoperculum was much 
expanded ; while there are remains of a suboperculum 
and very slender branchiostegal rays on the left. The 
vertebrae in the abdominal region bear the expanded 
neural arches, and also short, slender ribs. The 'Column 
is distorted just behind the dorsal fin. Imperfect remains 
of all the fins occur, including the large and fringing 
rpointed caudal fin. The squamation is not well preserved ; 
but one longitudinal series of scales near the ventral 
border is conspicuous, apparently by its being thickened, 
not enlarged. The latter series doubtless indicates the 
course of the lateral line. Leivis Coll. 
46529. Imperfect specimen, specially displaying the vertebrae and 
pelvic fins. The short and deep vertebral centra are 
marked with delicate longitudinal ridges. The ribs are 
short and slender, not suppoifed by any transverse pro¬ 
cesses. The laminar neural arches in the hinder two 
thirds of the abdominal region are overlapped by extremely 
slender, separate neural spines. Lewis Coll. 
46560. Distorted fragment, showing robust clavicles, also remains 
of paired and dorsal fins. Lewis Coll. 
