Hydroids (Cnidaria, Hydrozoa) of the Danish expedition to

228
based his description of Lytocarpia graffei on a
small, juvenile colony. The colony was monosiphonic
and had no gonothecae. It must be considered
as unrecognizable. Stechow (1919) distinguished
it from M. balei on account of the
shape of the bottom of the hydrotheca: rounded
in M. balei, with a step in Lytocarpia graffei. This
character is of little use, as usually all intermediates
can be found in Macrorhynchia colonies.
Leloup (1930b) also contested Stechow’s view,
however, Leloup’s (1930b: fig. 6) material of M.
balei appears indistinguishable from M. philippina
because his figures show a thick, triangular
intrathecal septum. Hirohito (1983, 1995) again
described Japanese material of M. balei. Hirohito
distinguished his material from M. philippina
solely on account of the length and thickness of
the intrathecal septum. However, the figures of
M. philippina given by Hirohito (1983, 1995),
are more typical for M. balei: the upright lateral
nematotheca and the numerous gonothecae on
the phylactocarps. Because Hirohito (1983) also
described female gonothecae containing planulae,
thus being larviparous and not releasing
medusoids as seen in typical M. philippina, it
seems more likely that this material was also M.
balei. Hirohoto’s material should be re-examined
for the presence of nematopores.
Distribution
Hawaii, Indonesia, Philippines, Japan. Type locality:
Off south coast of Molokai, Hawaiian
archipelago, 86–210 m.
Macrorhynchia singularis (Billard, 1908)
Fig. 72.
Plumulariidae spec. IV von Campenhausen 1896b: 317, pl.
15 fig. 5.
Lytocarpus philippinus var. singularis Billard, 1908b: 112,
figs A–B.
Lytocarpus singularis Billard, 1913: 79, figs 64–65.
Lytocarpus balei. – In part Stechow 1909: 99, pl. 6: fig. 12.
– Stechow 1919: 134.
Material examined:
Kei Islands Expedition stations: 18. – 40. – Kei Islands
Expedition, Bay of Ambon, 45–90 m, 2 Mar 1922. – Kei
Islands Expedition, Bay of Ambon, 90 m, 2 Mar 1922.
Differential diagnosis
Similar to Macrorhynchia philippina, but colo-
P. SCHUCHERT
Fig. 72. Macrorhynchia singularis (Billard, 1908); station
40. A. First internode of hydrocladium, note enlarged lateral
nematotheca (dotted: nematocyst). B. Second segment of
hydrocladium with characteristic thick median inferior nematotheca.
– Scale: A–B 50 µm.
nies smaller (up to 10 cm), one lateral nematotheca
of first hydrocladial segment much enlarged
and directed towards rear, opposite nematotheca
of same segment small, free part of
median nematotheca very short; median nematotheca
of segments distal to first one mostly
much enlarged and thick, lateral nematothecae
usually small. Some lateral nematothecae of
more distal segments can also be enlarged on one
side, as well as some median inferior nemat-