HYDROIDS OF THE HAWAIIAN ISLANDS. 
951 
Plumularia corrugata Nutting. 
Locality . — Station 4102, north coast of the island of Maui, 122 fathoms. 
This specimen agrees closely with those collected by Richard Rath bun off the coast of Brazil. 
Plumularia corrugata Nutting, American Hydroids, 1900, Part I, 64. 
Plumularia j or dani Nutting, new species. 
(PI. vi, fig. 5; pi. xii, figs. 1-2.) 
Trophosome . — Colony dark in color, rigid in habit, flabellate in form; main stem fascicled, strongly 
geniculate; branches arising from peripheral tubes, nearly straight, fascicled proximally, simple 
distally, bearing pinnate branch lets which, like the distal parts of main branches, are divided into 
regular internodes, each of which bears a hydrocladium on a strong process near its distal end, the 
process showing a conical protuberance on its upper side. Hydrocladia subalternate, those on each 
side being alternately raised and depressed, as viewed under the lens, so that the hydrocladia on each 
side occupy two distinct planes, a very exceptional character. Hydrocladia divided into regularly 
alternating hydrothecate and intermediate internodes, the former being about twice as long as the 
latter and bearing hydrothecse just below their middle. Hydrothecse small, cylindrical, margin 
even, scarcely flaring. Nematophores large in proportion to the hydrothecse, the supracalycine pair 
arising from a point above the hydrothecal margin; a mesial nematophore on the proximal end of 
each hydrothecate internode, another near the proximal end of each intermediate internode, and a 
pair on the upper side of each of the processes from the stem or branch supporting hydrocladia, 
these being the only cauline nematophores. Hydranths very large, not capable of retracting within 
the hydrothecse. 
Gonosome . — Not known. 
Locality . — Station 3936, near the island of Laysan, 79 to 130 fathoms. 
This species is unique among the Plumularidae in the disposition of the hydrocladia in two planes 
on each side, and is of a peculiarly stiff and rigid habit, and the main stem is more plainly geniculate 
than in any other species of the genus with which I am acquainted. 
Plumularia delicata Nutting, new species. 
(PI. v, fig. 2; pi. xii, figs. 3-5.) 
Trophosome.— Colony attaining a height of about 6 inches. Stem simple, divided into regular inter- 
nodes each of which bears a hydrocladium from a process near its distal end. Hydrocladia divided 
into alternating hydrothecate and intermediate internodes, each of which has an internal chitinous 
thickening near each end and all of which are longer than in allied species, the hydrothecate inter- 
nodes being about twice as long as the others and bearing the hydrothecse a little above their middle. 
Hydrothecse cup-shaped, about as high as broad, anterior profile straight. 'Nematophores large, a 
supracalycine pair and 2 mesial ones to each hydrothecate internode, and 2 mesial ones to each inter- 
mediate internode. 
Gonosome . — Gonangia bottle-shaped, but stouter than those of P. setacea, borne on front of stem. 
Distribution . — Station 3842, south coast of Molokai, 495 fathoms; station 4072, north coast of the 
island of Maui, 56 fathoms. 
This species is nearest to P. palmeri Nutting, but differs in bearing 2 mesial nematophores, instead 
of 1, on each internode of the hydrocladia; and in having much longer intermediate internodes. 
Plumularia milieri Nutting, new species. 
(PI. v, fig. 1 ; pi. xii, figs. 6, 7. ) 
Trophosome .— Colony attaining a height of about 1 inch.-- Stem not fascicled, divided into regular 
internodes each bearing a hydrocladium from a strong process near its distal end. Hydrocladia 
divided into alternating hydrothecate and intermediate internodes, the former being considerably the 
longer and bearing hydrothecse a little above their middle; all internodes showing internal thickenings 
near each end, the thickenings appearing at first sight much like corrugations. Hydrothecse as in 
P. setacea, but more distant. Nematophores very loosely attached and often wanting, the supracaly- 
