74 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
Family PERISTEDIIDAE 
Subfamily PERISTEDIINAE 
Genus PERISTEDION Lacepéde 
PERISTEDION LONGICEPS, new species 
Fieurpn 16 
Depth 5% in body measured from snout tip inside rostral exten- 
sions; head 214, width 114. Snout 2 in head; eye 5%, 3 in snout, 
14% in interorbital; orbit 5 in head measured from snout tip inside 
rostral extensions; maxillary length 51%, reaches 34 in snout length 
as measured to eye; 3 pairs of barbels, front pair simple and longer 
posterior pair with several filaments, its length 2 in snout and mandi- 
bular pair shortest; teeth not evident, edges of jaws smooth; interor- 
Vij Uy > 
pe EZZ_>~ 
a Wane We 
Mi SS SS 
AS ef 
H. W.F. del 
Figure 16,—Peristedion longiceps, new species: Type (U.S.N.M. No. 99516). 
bital 444 in head measured from snout tip inside rostral extensions, 
broadly concave. Gill rakers 7+22, lanceolate, longer than gill fila- 
ments or 21% in orbit; several upper gill filaments rudimentary. 
Pair of very slender, slightly diverging rostral extensions, each 
little longer than snout, separated by broad interspace with nar- 
rowest part of contraction much wider than either of extensions; 
single low, strong, backwardly directed supraorbital spine each side; 
