REPORT ON THE OPHIUROIDEA, 65 



corners, outer edges straight, toucliing nearly their whole length, diverging inward, 

 where they are separated by a small triangular plate. There are small round primary 

 j)lates, widely separated by the finer disk scales. Genital scales short, wider without 

 than within, bearing along their entire margin long, flat, and closely-set papUlas, about 

 fourteen in number ; those towards upper surface much narrower than the under ones. 

 Two very minute arm spines, one situated low on the edge of the side arm plate, next 

 the tentacle pore, the other half-way up the arm. Tentacle scales curved ; from three to 

 four on either side of the large pores on the basal joints. Colour in alcohol, pale 

 yellow. 



Station 205.— November 13, 1874 ; lat. 16° 42' N., long. 119° 22' E. ; 1050 fathoms ; 

 grey ooze. 



Ophioglypha undata, Lym. (PI. III. figs 16-18). 



Ophiof/hjpha undata, Lym., Bull. Mus. Comp. ZooL, vol. v., part 7, p. 90, pL iv. tigs. 101, 102, 

 1878. 



Four minute blunt arm spines. Disk plates rough and lumpy, with rosette of large 

 primaries. Under arm plates pentagonal. Disk high. Basal under arm plates about as 

 long as broad. Arms high and rounded. 



(Type specimen from Station 176.) Diameter of disk 3 "5 mm. Width of arm close to 

 disk 1 mm. Five mouth papillae on either side, of which the three outer ones are squarish, 

 and the two innermost pointed and similar to the large one at apex of jaw. Mouth shields 

 five-sided, with outer lateral corners curved and a blunt angle within ; length to breadth 

 •7 : '5. Side mouth shields rather large, longer than wide ; wider without than within, 

 where they meet. First under arm plate long, three-sided, with angles much rounded 

 and lateral sides re-enteringly curved ; second and third five-sided, with outer corners 

 rounded, an angle inward, and lateral sides re-enteringly curved ; those beyond grow 

 rapidly smaller, but have the same general form. Side arm plates much swollen, but 

 constricted at their inner margin, meeting widely above and below beyond the disk. 

 The first upper arm plate is triangular, with outer edge curved ; the second diamond 

 shaped, having the inner angle slightly truncated ; beyond this they become rapidly 

 smaller and are diamond shaped. Disk plates above thick, and overlapping like tiles ; 

 in the centre is a rosette of the six primary plates, the middle one being pentagonal, and 

 those surrounding it transverse oval ; on the outer edge of each of these latter plates are 

 one large and two smaller semicircular plates ; in the interbrachial spaces are two large 

 rounded plates, the outer one extending quite to the margin of the disk. Eadial shields 

 about as broad as long, angular, closely soldered together. On the under surface the 

 plates are rounded, and so much swollen as to form knobs with furrows between, the 



(ZOOL. CHALL. EXP. — PAET XIV. — 1882.) O 9 



