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The adambulacral plates (Fig. 4.b) carry three spines, forming 
a transverse series in continuation of the inferomarginal series of 
spines. The furrow spine is small, slightly curved, compressed, 
saber-like. The two outer spines are placed close together; the 
inner of them is the largest, about as large as the marginal spines, 
Fig. 4. Luidia varia. a. Inferomarginals; b. adambulacral plates (the aclradial 
side is turned up, the distal side to the right); c. mouth plates (jaw) and 
first adambulacral plate, iu side view; d. paxillæ (of two different speci- 
mens; cf. text). a—c. ®/i; d. ®/i. 
slightly curved, not pointed. Adorally to these two spines is gener¬ 
ally found one much shorter and slenderer spine, more rarely two. 
The adambulacral plates are separated from each other by a rather 
wide membranous space. 
The mouth plates (Fig. 4.c) carry on each half an irregular 
double-series of spines which are stout and rather long in the 
proximal part, much shorter and slenderer in the distal part. A 
series of 4 small, siender spines is found orally along the vertical 
edge of the mouth plate, diminishing in size downwards, and an 
irregular group of 4—5 still slenderer spinelets is found on the 
middle of the vertical sidewall of the mouth plate. — The inter- 
mediate plates are small and only in a single series. Each carries 
a small group of, generally, 6—8 siender spinelets, one of them 
being sometimes slightly elongated. Farther out on the arm there 
are mostly only 3—4 spinelets on the intermediate plates; they 
are, especially in the interradial space, invested by a rather thick 
