REPORT ON THE OPHIUROIDEA. 49 



marrow line, bearing a close row of short, square papillae, which become larger and more 

 rounded where they form the arm comb. Three short, bluntly-pointed arm spines, 

 situated near the junction of the side with the under arm plate. Seven square, close-set 

 scales on each side of mouth tentacle pores ; the next two pairs have four on each side ; 

 the next one usually three on the inside and two on the other ; beyond the disk only one 

 on the inner side. Colour in alcohol, white. 



Station 237.— June 17, 1875; lat. 34° 37' N., long. 140° 32' E. ; 1875 fathoms; 

 mud. 



Ophioghjpha undulata, Lym. (PI. V. figs. 10-12). 



Ophioglypha undulata, Lym., BulL Mus. Comp. Zool., vol. v., part 7, p. 75, pi. iii. figs. 61, 62, 

 1878. 



Three very short, conical arm spines, standing on middle of edge of plate. Disk scales 

 coarse and rather thick. Radial shields broader than long, and joined. Papillae of arm 

 comb close set, flat, and with rounded ends. 



(Type specimen from Station 224.) Diameter of disk 12 mm. Width of arm close to 

 disk, without spines, 2*3 mm. Mouth papilla? four on each side, short and square and 

 closely set, the outer one widest ; at angle of the jaw usually a cluster of three conical 

 papillae. Mouth shield rounded triangular, much broader than long, with an obtuse angle 

 within, and outer side slightly curved ; length to breadth 2 - 3 : 2 - 3. Side mouth shields 

 nearly straight, rather long,' and meeting fully within. First under arm plate oval or 

 rounded hexagonal, and wider than long ; the next longer than any other, axe-shaped, with 

 long lateral sides re-enteringly curved and outer side curved ; those beyond grow rapidly 

 shorter, and beyond the fourth are separated by the side arm plates, which are regular and 

 scarcely swollen, and meet above and below beyond the fourth upper arm plate. First 

 upper arm plate wide, semicircular ; the rest diamond shaped, with inner angle truncated 

 and the outer more or less curved. Disk high, covered with rather thin, irregular, curved 

 plates, among which may be seen a central five-sided primary, and a large wide plate on 

 the margin of the disk, much broader than long. Radial shields rudely semicircidar, and 

 meeting only at their outer points, diverging inward, where they are separated by a small 

 triangular plate. The interbrachial space on the under surface is covered by the rather 

 long and narrow genital scales, which are broken in two, and bear no papilla?, and by 

 two large irregularly curved plates, between which and the mouth shield are from one 

 to three little scales. Arm spines three, short, veiy small, conical, situated half-way on 

 the outer edge of the side arm plate. Tentacle pores, except the first pair, small and 

 narrow. The first bears about three scales on each side ; the second, the same ; the 

 third, two ; and the fourth, one minute scale on the outer and two on the inner side. 

 Colour in alcohol, disk pale grey, arms white. 



(zool. CHALL. EXP. — PABT XTV. — •1882.) 7 



