MONOGEArH OF JAPANESE OPHIUEOIDEA. 45 



tlio two rather large, nearly parallel genital slits. On the floor of 

 each notch, opens one madreporic pore. Oral angles convex late- 

 rally and downwards, almost filhng up the oral slits. Eleven 

 or twelve teeth in a single vertical row, triangular and stout. On 

 either side of the oral angle, there are several flat, smooth, pave- 

 ment-like grains corresponding to the oral papillae. 



Arms long and slender, as high as wide near the base, not 

 smoothly rounded, but inclined to be quadrangular in transverse 

 section, wider above than below ; more distally arched above and 

 plane below, higher than wide ; closely covered with fine, smooth 

 granules, of which three or four lie in 1 mm. on the dorsal side 

 near the arm base. Arm joints rather distinct. First tentacle 

 pore without arm spines, next three or four pores with one, and 

 the rest with two spines. The abradial spine is very small, 

 conical, enclosed in skin, with rough end. The adradial one is 

 short and conical in the basal joints ; more distally they become 

 longer, stouter and club-shaped, finally about as long as two arm 

 joints ; enclosed in skin, rough ; the minute thorns at the end of 

 the spines become distally rather concentrated on the inner side 

 of the spines. Oral tentacle pores and some ten basal tentacle 

 pores opening by means of tubes, in which they are enclosed ; 

 each tube, except that of the oral and the first tentacle, is attached 

 to the adradial arm spine on its adradial side. 



Colour in alcohol light pinkish brown or flesh-coloured. 



This species is quite near to A. rubrum Lyman, but differs from 

 it cliiefly in the much coarser granules on the basal parts of the 

 arms, in having tentacle tubes not only for the oral tentacles but 

 also for some ten first tentacles, and in the club-shaped and rela- 

 tively longer and stouter arm spines. 



