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plates arc arranged without any definite order, and along the 

 borders of which the relatively large papulae are situated. These 

 arc comparatively few in nunil)er and extend in two irregular 

 rows along the carina of each arm and almost reach the apex. In 

 a specimen whose K=27 mm. there were 15-17 papulae to each 

 arm and one or two to each interradius, while in another with 

 K=32 mm. there were about 27 papula? to each arm. Each papala 

 is surrounded by small plates different from the rest of the abactin- 

 al surface and stands out conspicuously. The anus may also be 

 tolerably distinct, but the madreporite is very smaU, circular in out- 

 hne and is covered with a small number of radiating furrows meeting 

 in the centre. In alcoholic specimens it appears as an opaque white 

 body near the anus, while the rest of the body is transparent. The 

 stomach shows through the body wall as a roundish sac, and is 

 larger than the central pentagonal area referred to above. 



In well preserved specimens the plates of the central pentagon 

 of the abactinal side are marked off from one another by narrow 

 but distinct smooth grooves. The plates are of different size and 

 shape and are, as ah'oady mentioned, without any definite arrange- 

 ment, although in some places, traces of their arrangement in 

 concentric rings around the anus may be made out. Each plate bears 

 on its surface a number of groups of short paxilla-likc spinelets, the 

 number of these groups varying from about a dozen on the larger 

 plates to about half as many on the smaUer ones. The plates 

 immediately around the anus is very small. The plates of the 

 papular areas of the arms are much smaller than those of the 

 central pentagon, are also without any regular arrangement and 

 mostly bear each a single tuft of short spinelets similar to those 

 of the central pentagon. 



