Uropterygius Eels - — Goslime 
223 
The posterior position of the anus and the 
plain brown color together are said to be dis- 
tinctive. The other two plain brown species of 
Uropterygius do not seem to reach more than a 
foot in length whereas our specimen of U. 
sealei is 3 feet long. The dentition of the avail- 
able specimen is somewhat mangled. Appar- 
ently unknown outside of the Society and the 
Hawaiian Islands. 
Uropterygius tigrinus (Lesson) 
Table 1, Fig. la 
type locality: Society Islands. Several 
specimens examined from Johnston Island 
and the Hawaiian chain, 27 to 34 inches 
in length. 
The posterior position of the anus, together 
with the round black markings on the sides, 
is distinctive. The great similarity between 
U. tigrinus and U. polyspilus will be discussed 
under the latter species. In tooth pattern, 17. 
tigrinus and U. sealei are very similar and differ 
from all other members of the genus. The 
teeth of the inner maxillary row, those on the 
vomer, and the larger premaxillary teeth are 
all subequal in size. The inner maxillary and 
premaxillary teeth are distinctly separated by 
a gap which is not much smaller than that 
separating the vomerine teeth from those on 
the premaxillary. The mandibular teeth are 
biserial but the inner row stops short of the 
front of the eye. 
Uropterygius polyspilus (Regan) 
Table 1, Fig. lb 
TYPE locality: Tahiti. Two small speci- 
mens available from Johnston Island and one 
17-inch individual from Honolulu, Hawaii. 
The young of this species, up to at least 8 
inches in length, may be recognized immedi- 
ately by the abruptly light snout (yellow in 
life). However, the 17-inch specimen, which 
agrees with small specimens in other respects, 
lacks the light snout; its color pattern is an 
almost exact duplicate of that of U. tigrinus. 
Indeed the specimen was identified as U. ti- 
grinus until the relatively forward position of 
the anus was noted. (Because of this similarity 
of color pattern the original description of U 
tigrinus was checked to see that it did not 
really represent this species. Fortunately the 
description states that the anus is two-thirds 
of the way back along the body, which elimi- 
nates this possibility.) However, the dentition 
a b c 
d 
g 
Fig. 1. Diagrammatic representation of dentition of a, Uropterygius tigrinus; b, U. polyspilus; c, U. supraforatus; 
d, U. fuscoguttatus; e, U. inornatus; f, U. makatei; g, U. knighti. Each dot represents a tooth; upper jaw above, lower 
jaw below. 
