NO. 29 A NEW GENUS OF STARFISHES CLARK 3 



the Other. From each of these five large interradial plates two 

 regular rows each composed of nine elongate swollen plates run to 

 the arm tips. The proximal plates in these rows, slightly overlapping 

 the large interradial plates, are in contact or nearly so ; from this 

 point the rows diverge, each row bounding the abactinal surface of 

 an arm. The plates at first are about three times as long as broad, 

 but they gradually become shorter and at the arm tip are little, or 

 not at all, longer than broad. They are much swollen with high 

 broadly rounded crests, and imbricate adcentrally. Between each two 

 of the large interradials, and therefore between the innermost plates 

 of the two rows running down each arm, is a plate similar to the 

 latter, but somewhat smaller. At the distal end of this on either side 

 and partially overlapping it are two similar but slightly smaller plates 

 lying between the line of union between the first two plates in the 

 two outer rows. Beyond these are three plates forming the bases of 

 three regular rows running to the arm tips. The plates of the central 

 row alternate with the plates of the two outer rows. Each row in- 

 cludes usually nine plates. The plates in these three rows, which fill 

 the area between the two outer rows on each arm, are somewhat 

 more than half as large as the plates in the outer rows ; like them, 

 they are highest at the inner ends, and imbricate adcentrally. The 

 elongate swollen central or inner portion of each plate is well sepa- 

 rated from that of the plates adjacent. In the interradial areas a 

 rather broad deep groove runs downward to the abactinal surface. 

 Outside each of the rows of plates bordering the abactinal surface 

 of each arm from the second to the fifth plate in each row, runs a 

 row of four plates resembling those in the central portion of the 

 abactinal surface of the arms but narrower. Outside of this row, 

 opposite the junction between the first and second and second and 

 third plates, are two similar but smaller plates. 



The superomarginals are seven in number and form a regular row. 

 They are intermediate in size between the plates of the rows bordering 

 the abactinal surface of the arms and the lateral plates of the arms, 

 but are somewhat broader and more regularly swollen, appearing 

 more or less oval. They are about half again as long as their greatest 

 width. They are oblique in position, the actinal ends being more 

 distal than the abactinal, their long axes making an angle of about 

 60° with the line of the row as a whole. Below each superomarginal 

 is an inferomarginal. The inferomarginals are produced outward in 

 the form of a stout pillar with parallel sides and a broadly rounded 

 tip that is about twice as long as broad at the base. The first three 

 or four of these pillars are sepa'rated by about their own width, but 



