78 
PACIFIC SCIENCE, Vol. VIII, January, 1954 
Lateral line in two sections, with some evi- 
dence of a supplementary third section above 
in front. This uppermost line consists of about 
six papillae running along either side of nape 
from behind the occiput to just in front of 
level of dorsal origin. Upper major lateral line 
running backward from lobe above opercle, 
following contour of back and then bending 
downward posteriorly, ending above origin 
of about fifth anal ray. Lower lateral line com- 
mencing above anal origin and continuing 
along mid-sides almost or quite to posterior 
end of body. All three lateral lines apparently 
composed of papillae that project through 
the scales. 
Vertical fins scaleless, but a lobe of scales 
projecting on to base of pectoral. Dorsal 
originating well behind pectoral base, its rays, 
and also those of anal, all low but highest 
about middle of fin. Dorsal and anal rays 
enclosed in skin for most of their length, but 
this fleshy sheath not forming a prominent 
band as in Diplacanthopoma. Caudal rays pro- 
jecting well beyond dorsal and anal rays. Pec- 
torals badly frayed, but apparently short and 
broad. Just above pectoral base a blunt, con- 
cealed, backwardly directed point on clei- 
thrum. Pelvics originating under preopercle, 
reaching less than half way to anus. 
A single, short, pointed, pyloric appendage. 
No pseudobranch. 
Head and pectoral base bluish black. Body 
brownish. Pectoral rays and membranes en- 
closing bases of dorsal and anal black. Pro- 
jecting sections of dorsal and anal light. 
C. hawaiiensis differs from C. messieri Giin- 
ther in a number of minor respects. The anus 
is well forward of the middle of the standard 
length in C. hawaiiensis (it is median in C 
messieri). The head appears to be flatter and 
broader forward, with the eyes more upwardly 
directed than in Gunther’s species. The eyes 
are also nearer the front of the head, so that 
the snout plus eye (measured over a horizontal 
plane for comparison with Gunther’s plate) 
is contained about two times in the post- 
orbital head against about 1.6 times in Gun- 
ther’s plate of C. messieri. The head length is 
considerably more than half the distance from 
snout tip to vent in C. hawaiiensis, less than 
half that distance in C. messieri. The dorsal 
origin lies behind the mid-point between 
snout and vent in C. hawaiiensis, over it in 
C. messieri. Finally, the dorsal and anal of the 
Hawaiian species seem to differ in being 
lower, in having fewer rays, and in being 
scaleless (Gunther’s plate of C. messieri shows 
scales on the bases of the vertical fins). 
Cataetyx hawaiiensis differs from Gilbert’s 
description of C. rubrirostris (in Jordan and 
Evermann, 1898: 2505) in two major features 
and in dimensions. In C. hawaiiensis there is 
no "short, sharp spine directed backward im- 
mediately behind posterior nostril’’; instead, 
the posterior nostril opens out from what 
appears to be a bony trough just in front of 
the eye with a single row of scales separating 
this nostril from the orbit. In C. rubrirostris 
there are said to be "about 135 transverse 
series’’ of scales; in C. hawaiiensis the scales 
are more or less regularly arranged, and many 
of them have been lost from the holotype; 
nevertheless, four counts made of the trans- 
verse series ranged from 190 to 235 scales. 
In dimensions C. rubrirostris would appear to 
have a larger eye, shorter snout, and narrower 
interorbital. 
In the shape of the head C. hawaiiensis re- 
sembles C. laticeps Koefoed {loc. cit.) more 
than it does C. messieri. But C. laticeps, like 
C. messieri, is said to have the anus under the 
middle of the standard length rather than far { 
forward as in C.* hawaiiensis. In addition, C. | 
laticeps is said to have the posterior nostril j 
well in front of the eye and to have nine 
branchiostegal rays (seven in C. hawaiiensis) . j 
Genus VOLCANUS nov. ' 
Type species: Volcanus lineatus n. sp. ‘ 
Body tapering, but with a truncated pos- j 
terior tip at the end of the two well- developed f 
hypurals. Caudal rays considerably exserted. ' 
Lateral line single, incomplete, running along 
surface of body as a continuous fleshy tube J 
