BULLETIN OF THE 
Ophiomusium Lutkeni sp. nov. 
Plate V. Figs. 138-140. 
Special Marks. — Disk covered by large, angular, smooth, swollen plates, of 
which the interbrachial marginal is largest. Arms wide and thick, with side 
arm-plates much swollen and rounded, and bearing a spine on their upper 
surface. 
Description of an Individual (Station 192). — Diameter of disk 13 mm. 
Length of arm about 45 mm. Width of arm close to disk, without spines, 
2.5 mm. Four or five large square mouth-papille on each side, with one, 
small and slender, at apex of jaw, all closely joined, those without being deeper 
than those within. Mouth-shields rudely three-sided, having a blunt angle 
within and a curved outer edge broken by angles. Length to breadth 2.5 : 2.7. 
Side mouth-shields longer than broad, and thick, meeting well within, where 
they are slightly narrower than without. First under arm-plate small, nearly 
square, with all four angles rounded ; the next two larger, pentagonal, with an 
angle inward, outer lateral corners rounded, and deep re-entering curves on 
the lateral sides, where the tentacle-scales stand ; the under arm-plates beyond 
these are minute and triangular, having an angle inward and the outer edge 
slightly curved. Side arm-plates large, swelling without into a rounded ridge 
and forming the greater part of the covering of the arm. Upper arm-plates 
triangular, with an angle inward, and all three sides slightly curved. Disk 
massive and flat, covered with thick, slightly swollen plates, one pentagonal 
primary in the centre, surrounded. by five rudely hexagonal plates ; interbra- 
chial spaces filled by one hexagonal plate within, and a smaller quadrangular 
extending to the very large marginal plate, which is much swollen and has a 
constriction on the outer edge. Radial shields large and angular, wider with- 
out than within, with outer angles rounded, separated their entire length within 
by an hour-glass-shaped wedge of three small plates. Lower interbrachial 
space covered by the great marginal plate, the broad genital scales extending 
from the mouth-shield to the marginal plate, and by three intermediate plates. 
There are two short blunt arm-spines, besides a supplementary spine on the 
top of the side arm-plate. Tentacle-pores at the second and third under arm- 
plates only, with one small round scale on each pore. Color in alcohol, 
grayish. 
By its general shape, and by the extra spines on top of the arm, this species 
approaches O. acuferum, but is distinguished by form and arrangement of 
disk-plates. 
Station 192, 129 fathoms, 3 specimens. 
Ophiomusium validum ۰ 
Ophiomusium validum Dn. Goss, Vestindisk. Oph. Of. Kong. Akad. p. 618. 1871. 
Plate I. Figs. 7-9. 
Special Marks, — Most of the lower interbrachial space outside the mouth- 
shield is occupied by broad genital scales and a great central plate. No under 
