300 
PACIFIC SCIENCE, Vol. V, October, 1951 
lacrymal appears to be developed. In other 
genera examined the circumorbitals are re- 
duced to a series of ossicles enclosing the 
infraorbital canal, and the preopercle is 
usually almost rudimentary. 
OPERCULAR APPARATUS. The opercular ap- 
paratus shows various degrees of reduction in 
the ophichthids examined. In general, the 
body of the operculum lies mostly or entirely 
below its articular facet, though it projects 
upward to a considerable extent in Brachy- 
somophis (Fig. 2a) and, to some extent, in 
Caecula. The suboperculum and interoper- 
culum are wedge-shaped bones, but in 
Muraenichthys the suboperculum (Fig. 3^) 
sends out a backward projection that encloses 
the lower edge of the operculum. The pre- 
operculum is moderately developed in Bra- 
chysomophis, Leiuranus, and Cirrhimuraena, or 
is reduced to a tube for the lateral line canal 
in Muraenichthys and Caecula. In general, it 
may be said that the opercular system of 
Brachysomophis is the least, and that of 
Muraenichthys the most, specialized (or de- 
generate) . 
SUSPENSORIUM. The suspensorium of Murae- 
nichthys (Fig. 3^) differs from that of the other 
species examined in being somewhat for- 
Fig. 2. Brachysomophis henshawi. a. Bones of left 
side of head, hm, Hyomandibular; ic, infraorbital 
canal; io, interopercle; la, lacrymal?; ma, maxillary; 
op, opercle; pc, enlarged postorbital ossicle; pf, post- 
frontal; po, preopercle; pp, palatopterygoid; qu, 
quadrate; su, subopercle. Other labels as in Fig. lb. 
by Skull from left. Bones as in Fig. Ic. 
a 
Fig. 3. Muraenichthys {Muraenichthys') cookei. a. 
Head bones from right. Bones as in Fig. 2a. b, Skull 
from above. Nasal included on left side. Bones as in 
Fig. Ic. c, Skull from rear. Bones as in Fig. id. 
wardly inclined. In all, the palatopterygoid is 
a laminar bone more or less loosely attached 
to the hyomandibular and quadrate pos- 
teriorly, and by ligament to the maxillary 
laterally and the skull mesially. 
LOWER JAW. The lower jaw is inferior to the 
upper except in Brachysomophis (Fig. 2a) 
where it projects and, like the upper, bears 
large, sharp canine teeth. 
MAXILLARIES. The maxillaties articulate at a 
more or less variable distance from the tip of 
the rostrum, far forward in Brachysomophis 
(Fig. 2a), more posteriorly in the others. 
Usually the dentigerous part of the maxil- 
laries terminates well forward of the highest 
part of the dentary, though an ossified liga- 
ment may extend farther back. In Brachyso- 
mophis, however, the maxillary is a long, 
toothed bone extending back almost to the 
level of the lower jaw articulation; it is sup- 
ported above, as already noted, by the 
postorbitals. 
Another type of jaw specialization is found 
