66 
ACTIISrOPTEETGII. 
cranium is longer and narrower than in Clianos salmoneus, 
with the ethmoidal region attenuated and pointed. The 
quadrate hones are distinct behind the characteristic 
short, robust, and toothless jaws. The vertebral centra 
exhibit deep lateral pits. Fragmentary remains of all the 
fins occur, and the dorsal is shown to have been slightly 
deeper than long. The articulations of all the fin-rays 
are remarkably close. The remains of the squamation 
are obscure. Purchased, 1895. 
Genus ANCYLOSTITIjOS, Kramberger. 
[Djela Jugoslav. Akad. no. xvi. 1895, p. 42.] 
Head and trunk much laterally compressed and deepened. Mouth 
terminal; jaws very stout but toothless. Branchiostegal rays 
probably about 6 in number. Vertebrae in the type species about 
28 in the abdominal, 22 in the caudal region ; ribs stout. Pelvic 
fins arising opposite the anterior part of the dorsal, which is some¬ 
what extended but does not occupy more than the hinder half 
of the back; anal fin acuminate in front, opposed to the hinder 
portion of the dorsal; caudal fin deeply forked. Scales small, not 
pectinated. 
Ancylostylos gibbus, Kramberger. 
1895, Ancylostylos gibhus, D. G. Kramberger, loc. cit. p. 42, pi. ix. 
Tyioe. Nearly complete fish ; Griock Museum. 
The type species, attaining a length of about 0-3. Length of 
head with opercular apparatus somewhat exceeding half the maxi¬ 
mum depth of the trunk, which is about equal to the length from 
the pectoral arch to the base of the caudal fin. External head- 
bones and preoperculum finely granulated. Pectoral fins with 16, 
pelvic fins with 12 stout rays, the latter not much shorter than the 
former ; dorsal fin with about 33, anal with from 20 to 22 rays. 
Form. ^ Log. Upper Cretaceous : Mrzlek, Croatia. 
Not represented in the Collection. 
Genus ISTIEUS9 Agassiz k 
[Poiss. Foss. vol. V. pt. ii. 1844, p. 91.] 
Head and trunk much laterally compressed, but elongated, 
’ This name is first mentioned, without definition, by Agassiz, Poiss. Foss., 
Feuill. 1835, p. 56. 
