REPORT ON THE OPHIUROIDEA. 51 



Ophiorjlypha albata, Lyin. (PI. V. figs. 13-15). 



Ophioglijpha albata, Lym., Bull. Mus. Comp. Zool., vol. v., part 7, p. 77, pi. iv. figs. 95-97, 

 1878. 



Six short, blunt, peg-like, evenly-spaced arm spines. Arms narrow. Radial 

 shields short, and separated by one or two large rounded plates. Disk scales thin, 

 even and hard to distinguish. Papillae of arm comb close set, flat, and with rounded 

 ends. 



(Type specimen from Station 236.) Diameter of disk 10 mm. Length of 

 arm about 40 mm. Width of arm close to disk 2 mm. Three short, crowded 

 mouth papillae on each side, with one (or sometimes three) conical at apex of jaw. 

 Mouth shield pentagonal, having a blunt angle within and outer corners curved ; 

 length to breadth 1*5 : 1 "3. Side mouth shields narrow, meeting within; running 

 along inner angle of mouth shield, and passing beyond to join first under arm 

 plate, where they are widest. First under arm plate irregular transverse oval ; 

 second plate short, bell-shaped, wider without than within ; those immediately beyond 

 are five-sided, wider without than within, with outer edge curved, a blunt angle 

 inward, and inner lateral sides a little re-enteringly curved ; about half-way out on 

 the arm they become nearly triangular, broader than long, with outer angles much 

 rounded. Side arm plates broad, but little swollen, not meeting below within the disk, 

 widely separated above by the upper arm plates, of which the second and third are hexa- 

 gonal, while those beyond are lengthened, their two outer angles blended in a curve 

 and the inner side very short. Disk smooth and slightly arched, covered with thin, 

 rounded or angular, closely-soldered scales, the six primaries being a little larger and 

 separated by one or two rows of scales ; there is a transverse row of three large angular 

 plates extending along the margin and connecting the radial shields, which are longer 

 than wide, angular, widely separated by two or three large scales ; their outer points 

 may or may not meet : under surface covered by rows of thin, ill-defined plates, similar 

 to those above. Genital scales hidden by the disk scales - ; along their free edge is a 

 close row of short, bead-like papillae ; they become larger and more rounded where they 

 pass upward to make the arm comb, which is attached to the radial shield. Six short 

 blunt, conical arm spines, arranged along the entire margin of the side arm plate. The 

 pores of the mouth tentacles are large, and have four short close-set scales on either side , 

 the two next have three small rounded scales on the inner side ; those beyond have two. 

 There are also minute and not easily seen scales on the outer side of the second and third 

 pores. Colour in alcohol, white. 



Station 236.— June 5, 1875; lat. 34° 58' N., long. 139° 30' E. ; 775 fathoms; 

 mud. 



