SHALLOW- WATER STARFISHES 23 1 



of the type as i : 4.4. The lesser radius of the type is 15 mm. ; the 

 greater radius, 66 mm. ; breadth of rays at base, 18 mm. ; diameter 

 of madreporic plate, 3 mm. 



The whole dorsal surface and sides of the rays are evenly covered 

 with small well spaced pseudopaxillae, each of which bears a fascicle, 

 or more rarely a comb-shaped group of four to eight or more small 

 slender spinules, which stand nearly erect, and are nearly equal in 

 length. The pseudopaxillae arise from elevations of the plates and 

 are so spaced as to leave intervals greater than their own diameters, 

 thus giving the surface a rough papillose appearance; the pseudo- 

 paxillas are more closely arranged on the center of the disk than on 

 the rays. The madreporic plate is large and covered with rough 

 spinules in comb-like groups. 



Each of the interspaces on the rays bears a single large papula, 

 equal in diameter to or exceeding the pseudopaxillae ; similar papulae 

 occur between the ventral plates, where they form regular longitu- 

 dinal rows. On the actinal surface of the rays there are three regu- 

 lar longitudinal series of plates corresponding in number to the 

 adambulacral plates. The plates in the two outer or marginal rows 

 are oblong at the summit, and each bears an oblong group of slender 

 paxilliform spinules, arranged in two rows, and similar to those of 

 the back. The plates of the superomarginal row are somewhat 

 smaller than those of the inferomarginal, and the spinules are about 

 twelve to fifteen in number toward the base of the rays, while in 

 the latter there are from twenty to twenty-five spinules, which form 

 pretty regular comb-like groups ; these extend to the tips of the rays. 

 Each of the interspaces alternating between these rows of plates 

 contains a single large papula. Closely adjacent to the adambulacral 

 plates there is a row of smaller peractinal plates, each of which bears 

 a round group of small paxilliform spinules, ten to fifteen in number, 

 similar in size and form to those of the marginal plates. This row 

 of peractinal plates extends from the angle of the jaw nearly to the 

 tip of the ray. 



Each of the adambulacral plates bears a single small spine, situated 

 deep within and directly across the furrow, forming a single longi- 

 tudinal series, and also a transverse group, consisting of eight to 

 twelve round, blunt spinules, in two rows ; the three inner ones are 

 decidedly longer and larger than the rest, the innermost odd one 

 being the largest of the three, and standing erect on the extreme 

 inner angle of the plate, and therefore nearly at right angles to the 

 small spine within the furrow. The outermost spinules of these groups 



