MUSEUM OF COMPARATIVE ZOOLOGY, 219 
short, squarish, close-set mouth-papillo on each side of an angle, with 
one spearhead-shaped at the apex. Mouth-shield flat, of a rounded heart- 
shape, with a small peak within, and a curve without ; length to breadth 
3:27 mm. Side mouth-shields small, much wider without than within, 
where they just meet. First under arm-plate small and rounded ; the next 
three are as wide as long, with outer side curved and much wider than the 
inner, which is an obtuse angle; lateral sides re-enteringly curved opposite 
the tentacle-pores, The rudimerary plates beyond have a rounded triangular 
shape. Side arm-plates large, not swollen, meeting broadly below and above 
beyond the third upper arm-plate. First two upper arm-plates quadrangular, 
with inner angle truncated; beyond, they are diamond-shaped. Disk flat 
and five-sided, covered with large radial shields and thin plates and scales, 
The central primary plate, which is much smaller than the other five, is sepa- 
rated from them by numerous fine scales. Radial shields long triangular, 
slightly swollen, minutely tuberculated, having a rounded angle within, and 
outer edge curved ; separated their entire length by irregular rows of minute 
scales ; length to breadth 6.2 : 3. Interbrachial spaces above and below also 
filled by rows of scales, whereof one larger stands on the margin of the disk. 
Genital openings reaching about two thirds the distance to the margin, bounded 
on both edges by ten or more very small, rounded, closely soldered papilla, 
Three minute arm-spines. A small tentacle-scale on either side of each pore. 
Color in alcohol, pale straw. 
Station 29, 955 fathoms, 3 specimens. 
This species stands next O. archaster, from which it is distinguished by the 
covering of the disk, 
Ophiomusium testudo Lym. 
Ophiomusium testudo, Ill. Cat. Mus. Comp. Zoöl. Vol. VIII, Pt. II. ps, TL 
Figs. 6-8. 1875. 
Sigsbee, off Havana, 177 fathoms, 3 specimens (var. T. Sigsbee, off Havana, 
80 fathoms, 1 specimen. Station 45, 101 fathoms, 9 specimens, 
Ophiomusium validum Ly. 
Ophiomusium validum, Of. Kong. Akad. Dr. Gods Oph. p. 618, 1871. 
Station 2, 800 fathoms, 1 specimen. Station 16, 292 fathoms, 1 specimen. 
Station 29, 968 fathoms, 9 specimens, Station 33, 1568 fathoms, 1 specimen. 
Station 41, 860 fathoms, 1 specimen, 
These are identified by the original sent me from Stockholm through the 
courtesy of Prof. Lovén. 
Ophiomusium acuferum Lym. 
Ophiomusium acuferum, 111. Catal. Mus, Comp, Zoól. No. 8. Pt. II. p. 7, Pl. I. 
Figs. 1-5. 1875. 
Station 20, 220 fathoms, 1 specimen, Station 32, 95 fathoms, 5 specimens. 
