Brotulids Killed by 1950 Eruption — Gosline 
81 
fleshy sheaths. Head length greater than its 
distance from anus. Eyes lateral, with maxil- 
laries reaching almost an eye diameter beyond 
them. Snout without flaps or ridges, anterior 
nostril well back from its edge. Preopercle 
with four sharp points, between which the 
preopercular border is scalloped. 
Basibranchials with an almost continuous, 
median band of teeth of even width (divided 
into two sections above bases of third gill 
arch) running from base of tongue almost to 
base of lower pharyngeals, which are close 
together. 
About a dozen, hnger-like pyloric caeca. 
This specimen appears to be a female with 
small, undeveloped ovaries. The specimen 
either had spawned recently or it represents 
the immature form of a rather large species. 
Pycnocraspedum armatum differs distinctly 
from P. squamipinne, the only other known 
species in the genus, in having well-developed, 
sharp points on the preopercular border. Al- 
cock (1899: 84) says that P. squamipinne has 
"two or three rather indistinct points at the 
angle of the preoperculum,’’ but only one is 
shown in his plate (1895?, pi. 21, fig. 1). In 
addition, the dorsal fin of P. armatum origin- 
ates forward of (rather than behind) the pre- 
opercular border, and the pectoral fin reaches 
about to the anus. 
The .trivial name armatum (L.— armed) is 
given in reference to the spines on the pre- 
opercular border. 
INTERRELATIONSHIPS OF HAWAIIAN 
DEEP-WATER BROTULIDS 
In a family as large and varied as the Bro- 
tulidae, it is perhaps presumptuous to try to 
determine interrelationships from the five spe- 
cies at hand. Yet, to fail to do so would seem 
to be making incomplete use of available 
material, scanty as it is. The following brief 
discussion is therefore undertaken, with the 
full realization that any conclusions reached 
must remain highly provisional. The bases 
for these conclusions are summarized in 
Table 2. 
The five brotulids in the lava flow collec, 
dons would seem to fall into three groups- 
(1) the two species of Diplacanthopoma: 
(2) Cataetyx, and (3) Volcanus and Pycnocras- 
pedum. Arranged in this way, these brotulids 
form a series ranging from those with the 
head completely scaleless {Diplacanthopoma) 
to Pycnocraspedum with the head entirely 
scaled. On this character alone Volcanus, with 
the head partially scaled, would fall with Ca- 
taetyx, as it would if gill raker count, dorsal 
fin origin, or preopercular armature were used. 
However, I feel that Volcanus is more closely 
related to Pycnocraspedum because of similari- 
ties between these two genera in dentition, 
the position of the anterior nostril, the lateral 
line structure, and, to a slight extent, because 
of the development of a bifid pelvic filament. 
In the general classification of the family 
as erected by Radcliffe (1913) and Norman 
(1939), Pycnocraspedum occupies a somewhat 
dubious position somewhere between the ovi- 
parous forms with a fully scaled head and 
rather numerous well-developed gill rakers, 
and the viviparous forms with the head par- 
tially scaled or naked and only three devel- 
oped gill rakers (see Norman, 1939: 89). 
Unfortunately, whether Pycnocraspedum is 
oviparous or viviparous remains unknown. 
The same is true of Volcanus, though the 
numerous small eggs of the holotype of V. 
Uneatus bear far more resemblance to the eggs 
of the oviparous Brotula than they do to the 
few large eggs of the viviparous Dinematich- 
thys and Microhrotula. Indeed, Brotula itself 
demonstrates that there are oviparous bro- 
tulids with the head completely scaled and 
the developed gill rakers reduced to three. 
In view of these points the contingency is 
presented that between the "oviparous’’ and 
"viviparous" groups as drawn up by Norman 
(1939, key sections C and CC, pp. 80 and 82) 
there lies an intermediate group of oviparous 
genera with the head more or less fully scaled 
and the number of gill rakers more or less 
reduced. Such a possibility is not pleasant for 
makers of keys to brotulid genera to con- 
