410 
ACTIXOPTEKYGII. 
Genus MYRIPRISTIS, Cuvier. 
[Begne Animal, ed. 2, vol. ii. 1829, p. 150.] 
Trunk more or less elongated and laterally compressed. Frontal 
region of skull gently rounded, not ridged ; cleft of mouth small, 
mandible prominent, and teeth minute. Opercular bones serrated : 
operculum pointed or produced into a spine behind ; preoperculum 
without spine. Vertebrae 10-12 in the abdominal, about 15 in tbo 
caudal region. Pelvic fins with one spine and 7 divided rays, 
arising somewhat behind the origin of the pectorals. Dorsal fin 
much extended, almost or completely divided into two halves, the 
foremost spinous ; anal fin not much extended, with 4 spines ; 
caudal fin deeply cloft. Scales large and ctenoid, more or less 
uniform, extending over the cheeks and oporcular apparatus. 
A figure of tho skull of this genus is given by Agassiz, Poiss. 
Foss. vol. iv. pi. B. fig. 2. The oxisting species live at tho surface 
of tropical seas. 
Myripristis leptacanthus, Agassiz. 
1700. Perea formosa, G. S. Volta, Ittiolit. Veron. p. lxxx.pl- xvn. 
fig. 2 (err ore), 
1818. “ Perea formosa," II. D. de Blainville, Nouv. Diet, d’llist. Nat. 
vol. xxvii. p. 347. 
1838-39. Myripristis leptacanthus, L. Agassiz, Poiss. Foss. vol. iv. 
__ PP- r> > HI, pi. xv. fig. 4. 
1876. Myripristis leptacanthus, F. Bassani, Atti Soc. Veneto-Trent. 
Sci. Nat. vol. iii. p. 176. 
Type. Imperfect fish ; Palaeontological Museum, Munich. 
A species attaining a length of about 0T5. Length of head with 
opercular apparatus very slightly exceeding the maximum depth of 
the trunk, which is contained three times in tho total length to the 
base of the caudal fin. Operculum not produced behind into a spine. 
Spinous portion of dorsal fin, with 15 or 16 remarkably slender 
spines, more than twice as much oxtendod as the soft portion, which 
comprises about 15 divided rays ; anal fin more extended than the 
soft dorsal, the 4 spines gradually increasing in size, and followed 
by about 18 divided rays. Serrations of scales uniform. 
Form. <j- Loc. Upper Eocene: Monte Bolca, near Verona. 
P. 1940, P. 3937. Fine specimen, in counterpart, displaying all the 
fins. Eyerton <Sf Enniskillen Colls . 
P. 1940 a, P. 3937 a. Good smaller specimen, in counterpart. 
Egerton <$• Enniskillen Colls. 
