954 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Distribution .— Station 3939, north of the island of Laysan, 163 fathoms; station 3955, northeast of 
the island of Laysan, 20 fathoms; station 3961, south of the island of Laysan, 19 fathoms; station 3962, 
south of the island of Laysan, 16 fathoms. 
This remarkable species is represented 1 >y a number of fine specimens from the waters about 
Laysan. The corbula is so much like that of Aglaophenia in external appearance that it would deceive 
anyone who did not carefully investigate it. The trophosome also is almost that of a typical Aglaophenia. 
The black color is constant in all the specimens and is produced by a dense black pigment throughout 
the colony. 
Genus LYTOCARPUS. 
Trophosome . — Stem fascicled; hydrothecal margin strongly toothed or sinuous; mesial nemato- 
phores with 2 openings, cauline nematophores broad and triangular in outline. 
Gonosome . — Gonangia borne on hydrocladia, which are modified so as to form protective branchlets, 
often aggregated into a pseudo-corbula, with leaves formed by modified hydrocladia instead of append- 
ages to hydrocladia, as in the genus Aglaophenia. There is a hydrotheca at the base of each protective 
branch. • 
Lytocarpus phceniceus (Busk). 
This is one of the most common species in the collection, being found at the following stations: 
Station 3809, south coast of the island of Oahu, 125 fathoms; station 3814, off Diamond Head, Oahu, 
284 fathoms; station 3845, south coast of the island of Molokai, 60 fathoms; station 3848, south coast 
of the island of Molokai, 73 fathoms; station 3849, south coast of the island of Molokai, 73 fathoms; 
station 3939, north of the island of Laysan, 163 fathoms; station 3978, south of Bird Island, 32 fathoms; 
station 3979, south of Bird Island, 222 to 387 fathoms; station 3987, north of the island of Kauai, 55 
fathoms; station 4071, north of the island of Maui, 52 fathoms; station 4072, north of the island of 
Maui, 56 fathoms. 
Plumularia phxnicea Busk, Voyage of the Rattlesnake, Narrative, Appendix IV, 1852. 
Lytocarpus hawaiensis Nutting, new species 
(PI. v, fig. 6; pi. xii, figs. 10-13.) 
Trophosome . — Colony attaining a height of about 4 inches. Stem fascicled; branching pinnate, the 
branches distant and not fascicled, not plainly divided into internodes, bearing the alternate hydro- 
cladia. Hydrothecse ovate in general outline, margin with a rather prominent anterior tooth and 2 
small uneven lateral teeth on each side; intrathecal ridge obsolete. Supracalycine nematophores 
strong, regularly curved, reaching considerably above the hydrothecal margin; mesial nematophores 
moderate in size, regularly curved outward, and not nearly reaching the top of the hydrotheca; 
cauline nematophores very long and slender, 2 on the branch at the base of each hydrocladium. 
Gonosome . — Gonangia borne on branches which are modified into protective contrivances taking 
the form of sickle-shaped phylactogonia, 1 to each of the much-flattened gonangia. Gonangia borne 
on rows on the upper side of the branch, orbicular, but considerably broader than long when viewed 
from the flat side. The phylactogonia are armed with 2 rows of long conspicuous tubular 
nematophores. 
Distribution . — Station 3853, south coast of Molokai Island, 115 fathoms; station 3875, between 
Maui and Lanai islands, 65 fathoms; station 3848, south of the island of Molokai, 44-73 fathoms. 
Lytocarpus balei Nutting, new species. 
(PI. vi, fig. 1; pi. xiii, figs. 7, 8.) 
Trophosome . — Colony attaining a height of about 2 inches. Stem fascicled; branches irregularly 
alternate and fascicled, except on the distal parts; hydrocladia alternate, each with 2 strong septal 
ridges and 1 weak one opposite each hydrotheca. Hydrothecse oval in general outline, aperture nearly 
vertical, margin almost smooth, and a very strong intrathecal ridge usually reaching more than half- 
way across the hydrotheca and ending in a round knob. Supracalycine nematophores small, slender, 
reaching nearly to the hydrothecal margin; mesial nematophores very strong, and reaching consider- 
ably above the hydrothecal margin. 
