WEST INDIAN STARFISHES 29 



The central plate of the disk is surrounded by several small 

 plates, and by papular pores. 



All the plates of the disk and dorsal side of the rays are 

 thickly covered with minute rough spinules that leave little 

 round scars when rubbed off. 



Pedicellarige of the forficulate kind, much larger than the 

 spinules, are scattered over the whole surface, usually but one 

 to a plate. When closed they are ovate-lanceolate, and some- 

 what compressed, subacute. 



The median radial row of plates is conspicuous. They are 

 rather large, convex, with a small central boss, carrying a small 

 short, thick spine, which is somewhat enlarged or obtuse at tip ; 

 the distal ones are smaller and acorn-shaped. They are easily 

 detached and are often rubbed off. They are often absent from 

 the distal part of the rays. These radial plates are shield- 

 shaped, with rounded sides and overlap each other serially. 



The sides and lower surfaces of the rays are proximally made 

 up of seven to nine regular rows of small shield-shaped plates, 

 all much alike, except the first row, so that it is not easy to dis- 

 tinguish the marginal rows. The row next the median radials 

 has larger, angular plates, similar to the median, though smaller. 

 The others are imbricated transversely, in regular vertical rows, 

 decreasing in size downward, and overlapping with their angular 

 lower end, like slates on a roof. 



In five or six lower rows each plate bears on a boss, a long, 

 slender, very acute spine, decreasing upward in length, where 

 they nearly intergrade with the spinules of the upper plates. 

 These spines are also accompanied by small, acute spinules, and 

 each plate usually has a rather large lanceolate or acute-ovate 

 pedicellaria. Distally a similar spine appears also on the row 

 next to the carinal row. 



The adambulacral plates are alternately large and small. The 

 larger ones are carinated and project far into the groove and 

 bear, on the curved edge, five or six slender acute spines, of 

 which two or three are within the groove, one far within, and 

 the others form a divergent row, transverse to the furrow, the 

 middle or marginal ones longest. Many of these spines, both 

 within and outside the furrow, bear a single large, forficulate or 

 major pedicellaria, some of them much thicker and about as long 



