130 BULLETIN OF THE 



and euclosed by the \Wde outer mouth-papillce. Color in alcohol, very light 

 gray. 



Other specimens had the disk-scales more regularly disposed than in Fig. 

 159, and the radial shields pear-seed shape with an angle inward. 



Station 218, 1070 fathoms, 12 + specimens. 



OPHIOPHYLLUM* gen. nov. 



Disk extremely thin and flat, covered with scales and large radial shields, 

 and bordered by a row of plates which are movable and attached by their 

 inner margins. Mouth-papillas arranged in a close row ; no tooth-papillas ; 

 teeth. Arm-spines thin and broad, standing on outer edge of side arm-plate. 

 Two genital openings in each interbrachial space. 



This singular genus has small relationship with any other. The fringe of 

 thin plates is like that found in Podophora among echinodernis. 



Ophiophyllum petilum sp. nov. 



Plate VII. Figs. 179-181. 



Special Maries. — Fringe-like border of disk consisting of about a dozen very 

 thin plates in each interbrachial space. One arm-spine, which is wide and flat 

 like a plate of the border. No tentacle-scale. 



Description of an Individual (Station 174). — Diameter of disk 6 mm. 

 Width of arm, without spines, close to the disk 1.2 mm. Six small, short, 

 square, close-set mouth-papilloe on either side of an angle, and three smaller 

 diamond-shaped at the apex. Mouth-shields rather large fan-sbaped, with a 

 deep curve without and an angle within ; length to breadth 1 : 1.2. Side 

 mouth-shields narrow, bounding the inner angle of the mouth-shield ; outer 

 ends square, inner ends tapering and separated. First under arm-plate three- 

 sided, with a rounded angle inward, lateral sides straight, and outer edge 

 curved ; the rest are small and pentagonal, with an angle inward. Side arm- 

 plates broad and thin, meeting below beyond the second under arm-plate, and 

 just touching above beyond the third upper arm-plate. Midway of the arm, 

 where it is highly arched, they fonn most of its covering. Basal upper arm- 

 plates diamond-shaped ; those beyond become more or less triangular, with a 

 sharp angle inward, and outer edge slightly rounded. Disk flat and very thin, 

 the centre covered with fine, thin, irregular scales ; interbrachial space on 

 margin filled by one large three-sided plate, with an angle inward and outer 

 edge nearly straight. Eadial shields large, three-sided, longer than wide, with 

 outer angles slightly rounded, separated their entire length by a cluster of 

 irregular scales larger than those of the centre ; in the lower interbrachial 



♦ 6(pis, snako ; (pvWov, kaf. 



