70 THE VOYAGE OF H.M.S. CHALLENGER. 



there is a group of similar papillae ou the free outer end of the side niouth shield. The arm 

 spines are so short, thin, square, and closely soldered together as to look like a continuous 

 narrow border to the side arm plate ; in shape they resemble the arm comb, and are 

 about eight in number. The pores of the mouth tentacles have four or five scales on 

 each side, similar to the mouth papilliB ; the second has seven similar scales on the inter- 

 brachial side, and four on the other ; the third five and four ; the fourth four and three ; 

 beyond this three only on the inner or interbrachial side. Colour in alcohol, 1)rownish- 



yellow. 



Station 232.— May 12, 1875, ofi"Enosima, Japan ; lat. 35° 11' N., long. 139° 28' E. ; 



345 fathoms ; sandy mud. 



Ophioghjpha minuta, Lym. (PI. VII. figs. 10-12). 



OpMogli/pha minida, Lym., BuH. Mus. Comp. Zool., vol. v., part 7, p. 94, pi. v. figs. 117-119, 

 1878. 



Interbrachial space below covered by only one or two plates besides the genital scales. 

 Upper arm plates rudimentary or wanting. Tentacle pores of arm with only one 

 rounded scale. 



(Type specimen from Station 158.) Diameter of disk 5-5 mm. Length of arm about 

 12 mm. Width of arm close to disk, without spines, 1 mm. Six short, squarish, closely 

 set, longer than wide mouth papillse on sides of angle, and three short and bluntly pointed 

 at apex of jaw. Mouth shield as long as broad, having a slight constriction towards the 

 inner end, which is an obtuse angle, outer side widely curved ; length to breadth 1:1. 

 Side mouth shields longer than wide, meeting within, and there forming a long angle 

 inward ; outer edges narrower than inner. First under arm plate triangular, with rounded 

 angle inward, lateral sides having a slight re-entering curve, and outer edge gently curved. 

 Second under arm plate pentagonal, length and breadth about equal, having deep 

 re-entering curves on the lateral sides, a narrow obtuse angle within, and outer side 

 curved ; beyond the second the plates are triangular in shape, having an angle inward 

 and outer side curved ; they become rapidly less in size, and disappear beyond the fifth, 

 though the tentacle pores continue. Side arm plates long and thick, beyond the second 

 under arm plate forming almost the entire covering of the arm, as there are no upper 

 arm plates. Disk flat and round, with a central group of six primary plates, whereof 

 the middle one is pentagonal, while the five surrounding it are transverse oval ; connect- 

 ing these plates are minute triangular scales ; the interbrachial spaces above arc filled by 

 two large plates, the inner one broader than long, with outer edge straight, and inner 

 edge broader than outer ; the marginal plate has the inner edge straight, and the outer 



