4G2 s, GOTO : 



apical portion is abraded, there can hardJy be a doubt that 

 the jjlates were tipped each witli a l)hint spine. Between the 

 adcentral plates there are as many interradial plates of an elon- 

 gated, somewhat lozenge -shaped form. In line with the adcentral 

 plates there is, corresponding to each arm, a carinal series of 

 plates, wliich become gradually smaller towards the tip of the 

 arms, and two to four of wliich directly following each adcentral 

 plate are produced into spine-tipped tubercles, similar in .form 

 to it ])ut smaller. Parallel with the carinal series there are 

 two more rows on either side of the arms, which are continued 

 in the disk across the interradial lines onto the corresponding series 

 of the adjacent arms. The row next the carinal series is con- 

 tinued on to the adcentral plate, with one of the processes of 

 which it is connected. In the interbrachial arc there is a short 

 curved series of some elongated plates and another group of one 

 or two plates between the superomargiual plates and the outer of 

 the interradial rows of plates above mentioned. All the abactinal 

 plates are closely invested with very small granules, and some of 

 them may bear transversely elongated, valvate pedicellaria?. 



The meshes between the abactinal plates are also covered 

 over with small granules exactly similar to those of the plates, 

 and bear numerous elliptical or transversely elongated valvate 

 pedicellariœ, which are generally much smaller than those of the 

 marginal or abactinal plates (PI. XA', iig. 240). There are also 

 in the meshes numerous pai)ular })ores, whicli are generally very 

 distinct in the dried specimen. 



Madrqjoritc. — The madreporic plate is tolerably large and 

 elliptical in outline. Its surface is on the same level with the 

 general surface of the surrounding jjortions, and it is therefore 



