lie BULLETIN OF THE 



which begin the genital openings ; outer side straight. Side mouth-shields 

 short, wide, with curved sides meeting ^\•ithin ; 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 tbe 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 surfoce 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 tlie 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-papilla) seven on each side, with one, somewhat larger than the 

 rest, at the angle of the jaw. Moutli-shields large, ])entagonal, with an acute 

 angle witliin, and outer side straiglit ; length to breadth 1.5 : 1. Side mouth- 

 shields large, long triangular ; sides slightly curved, with narrow ends touch- 

 ing within. Genital scales 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 curveil ; there are only two besides the small one at the outer end 

 of mouth-slit. Side arni-])Lites thick, composing the entire covering of the 

 arm, with the exce])tion of the minute triangular upper arm-plate, which has 

 an atigle inward, and outer side curved, and disappears on the second or third 



