229, PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
than mw anny. very « anarmolly incised logy an amexallen mostentic lor pr nolone 
tion from the second brachial, and inwardly united for their anterior 
half, their free inward sides forming a straight line which is at right 
angles to their apposed edges; second brachial triangular, somewhat 
longer than broad; following brachials at first slightly wedge-shaped, 
broader than long, soon becoming triangular, as long as broad, and 
quadrate again and finally elongate distally; the distal edges of 
the joints project very slightly, making the arms somewhat rough. 
Syzygia occur between the third and fourth, ninth and tenth, and 
fourteenth and fifteenth brachials, and distally at intervals of three 
bifascial articulations. 
Color (in spirits).—Light purplish brown. 
Locality—Albatross Station No. 3992; Mokuaeae Islet bearing 
S. 54° E., 3.5 miles distant ; 400-500 fathoms; fine gray sand and mud. 
One specimen, much mutilated. 
Type.—Cat. No. 22684, U.S.N.M. 
Remarks—The four closely crowded columns of cirrus sockets in 
each radial area on the centro-dorsal distinguish this species at once 
from all the others of the genus; it is possibly nearest to P. bigradata, 
which also has four columns of cirrus sockets in each radial area, 
but in P. bigradata they are very small and widely separated, and 
the radial areas are strongly marked off, while in P. congesta they 
are very iarge, and the division lines separating the radial areas are 
obsolete. | 
Family THALASSOMETRIDA 
Genus THALASSOMETRA. 
THALASSOMETRA HAWAITIIENSIS (A. H. Clark). 
1907. Antedon hawaiiensis A. H. CLARK, Proce. U. S. Nat. Mus. X XXIII, p. 152. 
This species was not obtained by the Here in 1902, but has 
previously been taken among the Hawaiian Islands at the following 
localities: 
Albatross Station No. 3475.—Kaiwi Channel, southeast of Hono- 
lulu; 351 fathoms; fine white sand; December 6, 1891. 
Type.—Cat. No. 22653, U.S.N.M., from this station. 
Albatross Station Wo. 34T6. —_Same locality; 298 fathoms; sie 
white sand; December 6, 1891. 
THALASSOMETRA GIGANTEA, new species. 
Centro-dorsal large, conical, the apex blunt, divided by 5 inter- 
radial ridges into 5 radial areas, each with 2 columns of cirrus 
sockets, which are more widely separated from each other than from 
those of adjoining radial areas. 
About 30 cirri 60 mm. to 80 mm. long, stout, with 55 to 60 joints, 
the first 4 short, the fifth squarish, the sixth and seventh about half 
