SHALLOW- WATER STARFISHES 



149 



ceptibly into the dorsal spines on the high, rounded side of the ray ; 

 four of these rows may be counted, in which the spines are small, 

 slender, shorter, and more pointed than the ambulacral spines, and 

 surrounded at base by thick wreaths of minor pedicellariae, which 

 wreaths, in alcoholic specimens, touch each other at their bases. The 

 dorsal ossicles, with their interspaces, are mostly transverse in direc- 

 tion on the rays, and anastomose pretty closely, except that there is 



X24 



FIG. 7. 



Ctenasterias crtbraria. No. 6123, U. S. Nat. Mus. (Young). A, A jaw; a, a; a', a', apical 

 spines; p, p, pedicellariae; e, e, epiorals. B, Ventral spines; a, a, inner, and a' a', outer 

 adambulacrals; b, peractinals; c, c, inf eromarginals ; p, p', minor pedicellariae; p", adambu- 

 lacral pedicellariae; X 24. C, A group of dorsal spines, minor pedicellariae, and papular 

 pores, x 24. D, Pedicellariae; o, two of the minor sort; b, c, c', small major pedicellariae. 

 X 67. 



on each side a series of transverse membranous interspaces much 

 larger than the rest (often one-fifth the width of the ray) and each 

 containing from two to five papulae. The papulae elsewhere stand 

 singly, sometimes two together. The dorsal spines are very 

 numerous, minute, no thicker, and much shorter than the latero- 

 ventrals, and are more or less capitate ; they are somewhat variable 

 in size, and are arranged in groups on the ossicles. Among them are 

 considerable numbers of minor pedicellariae, which are often half as 



