110 BULLETIN OF THE 
which begin the genital openings ; outer side straight. Side mouth-shields 
short, wide, with curved sides meeting within ; length 1 mm. Genital scales 
large, semicircular, somewhat swollen, running from lateral corners of mouth- 
shield to margin of disk. There are only two under arm-plates besides the 
small semicircular one at the angle of the mouth-slit ; they are pentagonal, with 
an angle inward ; lateral and inner lateral sides straight; outer side slightly 
curved. Tentacle-scales on second and third plates small, circular, and situated 
at the inner corners. Side arm-plates swollen, forming the entire covering of 
the arm beyond the last under arm-plate, with the exception of minute upper 
arm-plates, which are triangular, with an angle within. Disk covered with 
closely soldered plates; in the centre of the upper surface is a pentagonal 
plate, surrounded by five rudely hexagonal, which are connected with the 
radial shields by plates somewhat longer than broad, between each pair of 
which are large angular scales. Radial shields shaped like a rounded pear- 
seed, much swollen, touching at their middle point, but diverging outward and 
inward, separated on either side of the point of contact by a small triangular 
scale; on the interbrachial disk-margin is an angular, much swollen plate, 
joining three of similar character, which, with the genital scales, cover the 
under surface of the interbrachial space ; at the base of the arm above are 
three small rounded scales. Arm-spines two, minute, blunt, and set low down 
on the edge of the side arm-plate. Color in alcohol, white. 
Amboyna, 100 fathoms, 1 specimen. 
Ophiomusium lunare sp. nov. 
Plate I. Figs. 4-6. 
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 
arm-plates beyond the third. Two minute arm-spines set back from edge of 
side arm-plate. Only one lower interbrachial plate. No upper arm-plates 
beyond second, 
Description of an Individual (Station 219). — Diameter of disk 7 mm. 
Width of arm, without spines, close to disk 1.5 mm. Length of arm about 
20 mm. Mouth-papille seven on each side, with one, somewhat larger than the 
rest, at the angle of the jaw. Mouth-shields large, pentagonal, with an acute 
angle within, and outer side straight ; length to breadth 1.5: 1. Side mouth- 
shields large, long triangular ; sides slightly curved, with narrow ends touch- 
ing within, Genital seales long, with interbrachial side curved, starting at the 
inner corner of the genital opening and touching the radial shields with their 
outer ends. Under arm-plates pentagonal, with an angle inward, and outer 
side slightly curved ; there are only two besides the small one at the outer end 
of mouth-slit. Side arm-plates thick, composing the entire covering of the 
arm, with the exception of the minute triangular upper arm-plate, which has 
an angle inward, and outer side curved, and disappears on. the second. or third 
