312 
Fig. 6. Lateral view of right side of pectoral 
girdle. Cartilage stippled. ac» Actinost; cl, clei- 
thrum; co, coracoid; sc, scapula; si, su praclei (hr urn ; 
ur, upper pectoral ray. 
bear conical teeth. The openings between the 
first four gill arches are wide; that between 
the fourth and fifth is restricted. 
The pectoral girdle of Kaupicbthys (Fig. 
6) is rather well developed for eels. The 
supracleithrum ( si ) lies free in the flesh 
without articulation above or below. The 
cleithmm (cl) is a long, curved bone over- 
lying the forward end of the endoskeletal 
girdle. The coracoid (co) and scapula (sc) 
are embedded in a cartilaginous plate. There 
are four actinosts (ac) , of which three and 
a half articulate with the coracoid area. 
The vertebrae number approximately 98. 
Of these, about 20 lie ahead of the anus. 
However, the numbers of preanal and ab- 
dominal vertebrae are not the same, for the 
coelomic cavity of this fish extends posterior 
to the anus, as does the portion of the verte- 
bral column without closed haemal arches. 
The short centrum (ce) of the first verte- 
bra (Fig. la) has a rounded head fitting the 
socket of the basioccipital. It bears a neural 
arch ( na ) , which extends backward over the 
PACIFIC SCIENCE, Voi. IV, October, 1950 
centrum of the second vertebra. The second 
vertebra, in addition to the neural arch, has 
a median ventral projection. The third is sim- 
ilar to the second but bears a well-developed 
transverse process pointing postero- laterally. 
The neural arches of the first few vertebrae 
have crests with two to several dorsal spine- 
lets. These small spines drop out behind 
about the fifth vertebra. Farther back along 
the vertebral column each neural arch gives 
rise to a neural spine, these becoming well 
developed over the middle of the caudal por- 
tion of the vertebral column, but diminish- 
ing again posteriorly, and dropping out com- 
pletely over the last nine vertebrae. 
Over the whole rear part of the abdominal 
section of the column, the vertebrae develop 
broad, flat, lateral flanges. These, however, 
fail to bear ossified ribs. In fact, there appear 
to be no articulated ribs anywhere in the fish. 
Nevertheless, there are, in the caudal section, 
what appear to be long, slender, unarticu- 
lated epipleurals and epineurals for each ver- 
tebra (not shown in Fig. 7c). 
Posteriorly the haemal canal seems to stop 
at the seventy-eighth vertebra. The haemal 
spines (Fig. 1c, hs) continue to the ninety 
third. The final vertebra (Fig. lb and d) is 
extremely elongate. It appears to be made 
up in part of a rudimentary centrum, with 
neural and haemal arch, and in part of endo- 
skeletal elements (ee) of several fin rays. 
These endoskeletal elements form three 
groups united to the rest of the vertebra by 
a cartilaginous plate containing a large fora- 
men (fo). 
The heart lies just behind the gill arches 
and immediately before the level of the pec- 
toral girdle. 
RELATIONSHIPS 
The osteology of Muraenichthys closely 
resembles that of the Ophichthyidae (to be 
dealt with in a forthcoming paper) and dif- 
fers vastly from that of Kaupicbthys de- 
scribed above. The frontals of Muraenich - 
