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PACIFIC SCIENCE, Vol. V, October, 1951 
The skulls of the six genera examined also 
vary in the distance they project behind the 
supraoccipital. In Brachysomophis the skull is 
relatively truncate behind; in Myrichthys, at 
the other extreme (Fig. 5), a rather large sec- 
tion of the skull lies behind the supra- 
occipital. 
GILL ARCHES. The gill arches of species of 
Muraenichthys, Leuiramis, Ophichthus, Piso- 
odonophis {"Ophichthys boro”), and Myrichthys 
{”Ophichthys colubrinus”) have been briefly 
dealt with by Popta (1906). The gill arches of 
Myrichthys maculosus are illustrated in Figure 7. 
Fig. 7. Myrichthys maculosus. a. Outline of right side 
of hyoid apparatus from below, br, Branchiostegal ray; 
gl, glossohyal; uh, urohyal. h. Right gill arches from 
above, the upper parts opened out. Branchiostegal rays 
not shown. Cartilage areas stippled, bh, Basihyal; 
cb, ceratobranchial; ch, ceratohyal; eb, epibranchial; 
eh, epihyal; gc, gill cleft; gh, glossohyal; hb, hypo- 
branchial; Ip, lower pharyngeal; pb, pharyngobranchial; 
up, upper pharyngeal. 
Within the forms examined, the number of 
branchiostegal rays on one side are as follows : 
Caecula platyrhyncha, 17; Brachysomophis, 18; 
Cirrhimuraena, 24; Muraenichthys cookei, 26; 
Leiuranus, 28; and Myrichthys maculosus, 32. 
In all of these the branchiostegal rays of the 
two sides of the head overlap broadly on the 
midventral line. 
The pharyngeal teeth in all of these forms 
except Myrichthys are small, sharp, and de- 
pressible; in Myrichthys they are blunt and 
little movable. In all, the upper pharyngeals 
are shorter and broader than the lower, most 
notably so in Brachysomophis. In Muraenich- 
thys, Leiuranus, and Brachysomophis the lower 
pharyngeals are elongate and biserial; in the 
other three genera they are club-shaped to 
ovate. The number of teeth on a pharyngeal 
varies from 18 to 34 in the different forms. 
PECTORAL GIRDLE. The pectoral girdle seems 
always to be represented. Judging from X rays 
it is reduced to a cleithrum and possibly a 
supraclei thrum in Caecula. In Myrichthys a 
rudimentary bone which is probably the 
coracoid (Fig. 8) is embedded in a cartila- 
ginous plate. In Cirrhimuraena, scapula, cora- 
coid, and a single actinost are present as well 
as cleithrum and supraclei thrum. 
Fig. 8. Myrichthys maculosus. Left half of pectoral 
girdle from inside. Cartilage areas stippled, cl, Clei- 
thrum; CO, coracoid?; pe, base of pectoral ray; sc, 
supracleithrum. 
AXIAL SKELETON. Inasmuch as the nature of 
the vertebral column cannot be properly il- 
lustrated in its entirety, and as it has been 
used as a basis of family definition by Regan 
(1912: 386), it must be described in a general 
way. The following account is based pri- 
marily on Myrichthys, Brachysomophis, and 
Caecula. The first centrum is not fused to the 
skull; it is short, and its neural arch extends 
backward over the centrum of the second 
