SHALLOW-WATER STARFISHES 



141 



obvious radial rows, three on each side. The median row of spines 

 is distinct, but not prominent. The dorsal ossicles are openly reticu- 

 late, several surrounding each papular area, and bearing spines which 

 are so numerous as to be nearly in contact in circles around the 

 areas. They are not very diverse in size. Six to eight often stand 

 in a cluster on the larger ossicles. 



Fig. 6. 



Leptasterias epichlora plena, type, a, Group of dorsal spines; b, b', a pair of supero- 

 marginal spines on one plate; p. pedicellariae; c, c', inferomarginal spines; d, ;>€ractinal; 

 e, outer, and f, inner adambulacral spines with (p) minor pedicellariae. x 24. 



The superomarginal spines are similar and stand in groups of 

 two to four on a plate, besides one on the descending apophysis. The 

 two rows of marginal ossicles are separated by a row of large 

 papular areas, bearing small, acute major pedicellariae. 



The inferomarginal spines are longer, stouter, clavate, mostly 

 somewhat flattened, obtuse. They mostly stand obliquely, two to a 

 plate, forming a crowded double row. The peractinal spines are 

 stouter, shorter, more clavate and more flattened, one to a plate, close 

 to the adambulacrals. The latter are much more slender, two to a 

 plate. The outer ones are a little shorter than the inner, stouter, and 



