21 
are distinctly invested with ganoine in their exposed portion. Tlie vertehral 
centra are in the form of constricted cylinders, not completely severing the 
intervertebral portions of the notochord ; and they are often strengthened 
in the later species hy longitudinal streaks of hone on the periphery. The 
ribs are robust, extending almost or quite to the ventral border ; and some 
specimens seem to sliow that they arc attached to Inroad laminar parapophyses. 
The delicate neural arches in the abdominal region do not appear to have 
l)een fused with the centra, while the riglit and left lialves are separate. 
Above them, extending as far l3ackwards as tlie origin of the dorsal fin, is a 
series of short free rods, commonly interpreted as “ interspinous hones,” hut 
■^rhicli may even lie neural spines. There are also remains of some inter- 
mnseular ])ones. Both the neural and liannal arches in the caudal region 
are much more robust and firmly united with the centrum ; eacli consists of 
one piece, and has a laminar expansion at the base. 
The tin-rays are all delicate, articulated, and liranclied distally; and 
fulcra arc entirely absent. Tlie jielvie hones are laminar, broadest at the 
base for the attachment of the tin-rays, and thickened along the outer border. 
Owing to the varied cliaracter of the distortion produced hy crushing, 
it is very ditficult to determine the species of a genus of fishes like Leptolepis. 
Although there are sometimes marked differences in the skeleton, the external 
form and proportions of the fish must also he taken into consideration ; 
while the larger a collection the more impossible does it appear to separate 
the individuals into well-defined specific groujis. TTie arrangement of the 
Talhralgar Leptolepidae proposed hcloAv, must thus he regarded as provisional ; 
l)ut the present Writer is unable to recognise more than three well-marked 
forms. 
Leptolepis talp.ragarensis, s/l no>'. 
Plato Vr, Figs. 1-S. 
Ohs . — This is liy far tlie most abundant fish in the Talhragar deposit, 
and it is impossible to enumerate all the important sjiecimens elucidating its 
cliaracters. The following selection only is made for illustration ; — 
[a) A young specimen (PI. VI, Pig. 1) showing w'ell-separated vertebral 
rings, those in the anterior part of the abdominal region being over- 
turned and exhibited in end viewL 
[h] A larger fish (Pig. 2) appearing much more rolmst, hut its depth 
exaggerated hy crushing, especially at the ventral border. 
