MUR^ENID^. 
347 
P. 8952-53. Two portions of similar immature fishes ; Monte 
Eolca. Castdli CoJL 
P. 8951. Immature fish with very small head, apparently of the 
form named Leptocephalus medius by Agassiz, without 
definition (Neues Jahrb. 1833, p. 307); Monte Eolca. 
A similar fish seems to be figured under the name of 
Murcena cceca by Volta, op. ciL pi. liii. fig. 2. 
Castelli Coll. 
The following species have not been defined and are not repre¬ 
sented in the Collection :— 
Opliisiirus amticaudus., L. Agassiz, Neues Jahrb. 1835, p. 307 
(name only). Murcena opliis, G. S. Volta, Ittiolit. Veronese 
(1796), p. cliv. pi. xxiii. fig. 1 (errore). —Upper Eocene ; 
Monte Eolca. 
Spliagehranchus formosissimus., L. Agassiz, loc. cit. 1835, p. 307 
(name only). Ophidium barbatum, G. S. Volta, op. cif. 
(1796), p. clvii. pi. xxxviii. fig. 1.—Upper Eocene; Monte 
Eolca. 
The otolith described as follows seems to belong to this family:— 
Otolithus {Congeris) brevior, E. Koken, Zeitsehr. deutsch. geol. 
Ges. vol. xl. (1888), p. 293, pi. xviii. fig. 7.—Lower Ter¬ 
tiary ; Jackson Eiver, Mississippi. 
Suborder VII. PERCE&OCES. 
Vertebral centra always complete constricted cylinders, none 
coalesced. Siipraoccipital extending forwards between the reduced 
parietals; squamosal rudimentary and fused with the large pterotic ; 
mandible simple, each ramus consisting only of two elements (dentary 
and articulo-angular), rarely with a supplementary bone in the 
position of the coronoid. Pectoral arch suspended from the 
cranium ; precoracoid arch absent; infraclavicular plates absent; 
pectoral fin with not more than four or five basals. Pelvic fins 
abdominal, their supports never in contact with the clavicle. 
Eorsal fin with or without an anterior spinous portion. In the 
living forms—air-bladder closed, without pneumatic duct, in the 
adult (physoclystous) ; optic nerves decussating; intestine without 
spiral valve. 
Eor notes on the osteology of existing members of this suborder, 
see E. C. Starks, Proc. U.S. Nat. Mus. vol. xxii. (1899), pp. 1-10, 
pis. i.-iii. 
