308 s. goto: 



notch is present at the base on the inner side i.e. the side facing 

 the furrow (PL VI, fig. 92). On some plates the third spine is 

 replaced by two spines which are then smaller than when there 

 is only one (PI. VI, fig. 93c, d). . The pedicellaria is large and 

 rather conspicuous, being as long as the third spine. It has two 

 jaws and a conspicuous lunule near the base (PI. VI, fig. 93e) ; 

 each jaw would be triangular in cross -section, and has usually a 

 shallow groove on each external face i.e. the face turned away 

 from the axis of the organ. On the outer side of the third spine 

 and the pedicellaria there may be two or three smaller spines. 



The first and second adambulacrals have a somewhat 

 different armature from the rest. The pedicellaria is usually 

 absent, and in its place is found a spine similar in form to the 

 third spine. There are five or six more spines in the outer part 

 of the first plate and two or three in the corresponding part of 

 the second. 



Mouth-plates. — The mouth-plates are narrow and long with 

 an interspace covered over with a membrane. The most charac- 

 teristic point in the armature of the mouth-plates is the presence 

 of a pair of stout forficiform pediceUariœ at the mouth end of the 

 plates and of a second pair nearly on the same level with the first 

 but more removed from the mouth, projecting into the ambulacral 

 furrow (PI. VI, fig. 91). These pedicellaria3 are similar to those 

 of Luidia quinaria in similar positions, but are relatively thicker 

 and shorter, and the second pair project in this species more 

 distinctly into the ambulacral furrow than in L. quinaria. On 

 the actinal surface of each mouth- plate there is a series of six 

 or seven large, blunt spines along the inner margin (facing 

 the fellow-plate) and a second series of four or five similar 



