16G 



BULLETIN 82, UNITED STATES NATIONAL MUSEtTM 



In the other specimens the intersj'zygial interval is 3, sometimes 4, muscular artic- 

 ulations. The cirri are airanged in from one to three more or less complete rows. The 

 larger segments of the proximal pinnules may have prominent spiny frills at their dis- 

 tal ends. 



The color varies considerably from browns and graj's to reds and violets and may 

 be patterned with lighter bands on the brachials and cirrus segments or longitudinal 

 light bands on the arms or a generally paler calyx. 



Of two juvenile specimens with the arm length 3.2 mm. and 5 mm. respectively, 

 (he former lias a gap in the pinnulation after Pi, the basals are Ansiblc in the interradii 

 and remnants of the orals are present. The latter has lost the orals and Pj and P3 are 

 in process of development. 



In 14 individuals where the first genital pinnule was noted, it was P3 in 9, P4 in 2, 

 P3 or Pi in 2, and Pj or P3 in 1. 



The spccunens from San-Tu in the following tabulation appear to differ from the 

 rest in having more numerous cirrus segments, 15 or even 16, than in most other spec- 

 imens of comparable size. The brachials are not conspicuously spinous and the cirrus 

 segments are not markedly flared. However, Gislen (1922, fig. 107) has illustrated a 

 comparable cirrus and the arms of some of his specimens are also smooth. The spec- 



Tablb 5. — Range of variation in cirri and proximal pinnules of Antedon serrata 

 [Only the maxima of the cirrus counts were used in assessing the ranges] 



