SHALLOW-WATER STARFISHES IQQ 



the disk some of the ossicles may unite into a feeble network. Thick 

 clusters of minor pedicellariae are also scattered over the dorsal mem- 

 brane. In our larger specimens (see pi. xxx), there are also many 

 large major pedicellariae scattered over the dorsal integument, but 

 they are sometimes entirely lacking in young ones, up to 125 mm. in 

 diameter. They are compressed, long-ovate in outline, obtuse or sub- 

 acute, not dentate, often exceeding the spines in diameter (text- 

 fig. 2). 



The dorsal spines are sometimes partly short and obtuse, scarcely 

 longer than thick; most are long and slender, cylindrical or tapered, 

 rarely subclavate. They are often striated or grooved at the tip, but 

 more commonly are regular and subacute. They are more numerous 

 on the distal part of the rays, where they become very slender and 

 bear a thick wreath of minor pedicellariae at about mid-height. 

 Those on the disk have the wreath of pedicellariae around the base. 

 The superomarginal spines are similar to the dorsals, but a little 

 larger; they generally stand singly on alternate plates, and bear 

 thick wreaths of pedicellariae. The inferomarginal spines are longer 

 and stouter, often slightly enlarged at both ends, and mostly flattened 

 and obtuse or subclavate at the tip, two to a plate. 



The adambulacral plates are strongly compressed ; each bears a 

 single, very slender, slightly tapered, terete spine. Major pedicel- 

 lariae of different sizes also occur on the adambulacral plates, with 

 pedicels. Some of these are even larger than those on the dorsal 

 surface. They are similar in form, but are often more oblong- 

 ovate. The two apical peroral spines are stouter and much shorter 

 than the adorals; the side-spine is short and stout. The epiorals are 

 long and slender, tapered, longer than the adorals. The adoral 

 spines are decidedly longer than those more distal. 



The ambulacral feet are in four regular rows in half-grown and 

 mature specimens, except proximally and distally, where they are 

 nearly biserial. In quite small ones they are in two nearly regular 

 rows. 



The color, in life, is often bright red to reddish brown, but varies 

 from yellow, orange, and carmine to violet. 



Three large specimens from Puget Sound (coll. Professor Kincaid, 

 Mus. Comp. Z06I., No. 1908) have seventeen, eighteen, and twenty 

 rays, respectively. One much smaller specimen, from the same place, 

 has seventeen rays; and one about eight inches (200 mm.) in 

 diameter has eighteen rays. One about six inches (150 mm.) in 

 diameter has only twelve rays. Thus the number of rays does not 



