THE OPHIURID^. 



157 



slender^ apparently about ten times the diameter of the disk. Three 

 month papillae on ^ach side, besides tliose on the apex; the outermost 

 is very small; rounded, the next two are long and pointed ; inside these is 

 seen another pointed papilla, almost oh the level of the true mouth papilte ; 

 it belongs to the first mouth tentacle. Mouth shield inconsiderably broader 

 than long, inner end widely rounded, outer end restricted, corners rounded. 

 Side mouth shields almost equally wide in their .whole length, scarcely 



meeting within. 



First ventral plate as broad as the following ones, but much shorter, 

 hollowed within. Those beyond angular, a little longer than broad; they 

 are rather broadly in contact in the inner part of the arm, and have thus 

 the inner angle truncated; farther off they become separated, and then 

 have an obtuse angle within. The outer edge is made of three lines, which 

 form two obtuse angles ; the median one of these lines is slightly concave, 

 the two others straight. Inner laterals almost straight, outer re-enteringly 

 curved ; corners sharp. Side arm-plates with a rather prominent spine-ridge ; 

 there is a broad naked space separating the side plates of each two adjoin- 

 ing joints, also seen from the dorsal side. Dorsal plates a little more broad 

 than long (the inner ones not as broad as those farther off) ; they are usually 

 separated, but sometimes they are rather broadly in contact. They have a 

 .rounded angle within and outer edge curved; corners not rounded. 



Disk covered with numerous small, smooth, overlapping scales, among 

 which no primary plates are seen. The radial shields narrow, not half 

 the length of the radius of the disk, just meeting without or wholly sepa- 

 rated, without by a single elongated scale, w^ithin by some more irregidarly 

 placed scales ; they are pointed within, outer edge straight. There are a 

 few small scales outside the radial shields.. Under side of the disk covered 

 along the margin with scales similar to those of the dorsal side, on the inner 

 part more sparingly covered with scales, the naked skin being seen between 

 them. Along the margin there are some short spines, a few of them seen 

 from the dorsal side. Inner end of the genital scales distinct. Edge of the 

 disk rounded, the margin slightly concave. 



The inner joints have seven arm-spines ; farther out they gradually di- 

 minish in number, and in the outer part of the arm there are only three. 

 They are delicate, pointed, as long as an arm-joint or a little longer; the 

 upper and the lower ones usually are a little longer than the rest. One 



small rounded tentacle scale ; in the outer part of the arm there is none. 







