SEA LILIES, STARFISHES, ETC. — CLARK. 99 



differs much in different individuals and on different spines ; 

 occasionally they merge into more or less complete longitudinal 

 lines, but this is unusual ; they are often well developed on 

 the neck of the spine above the collar. The actinal primaries 

 have the collar very wide, and a thick, somewhat serrate 

 " cap " formed from the outer layer of the spine. 



The abactinal system is larger than the actinostome, but 

 the difference shows some diversity ; in the smallest specimen 

 the actinostome is little more than 8 mm., while the abactinal 

 system is nearly 12 ; in the largest specimen the measure- 

 ments are approximately 25 and 32 ; but in a specimen of 

 average size the measurements are only 18 and 20. 



The secondary spines show remarkable diversity of colour ; 

 in several specimens they are bright red, with those of the 

 ambulacra more or less greenish at both base and tip, and 

 those of the interambulacra with very slightly greenish tips. 

 In other cases they are reddish with purple tips and a longi- 

 tudinal purplish stripe, or they are dull flesh-colour with red 

 longitudinal stripe. In the largest specimens, all the second- 

 aries are more or less greenish, those of the interambulacra 

 with darker longitudinal stripe and pink or purplish tip, while 

 those of ambulacra are more nearly uniformly dark greenish. 

 Evidently no specific character can be drawn from the coloura- 

 tion of the secondary spines ! 



The occurrence of globiferous pedicellarise shows an equal 

 diversity ; in many specimens they are rare or wholly wanting, 

 but in the larger specimens they are generally present, at 

 least in the interambulacra, and in several of the biggest 

 specimens they are excessively abundant and very con- 

 spicuous, as they are white or pale greenish in colour. The 

 stalk is 3 mm. long (more or less) and has a very conspicuous 

 limb. The head is about a millimeter long and the valves 

 seem to be like those of P. baculosa. I have hitherto laid much 

 stress on the absence of globiferous pedicellarise in " Stephano- 

 cidaris bispinosa, A. Agassiz," but evidently the two specimens 

 previously seen by me were misleading. I can no longer 

 doubt that this species and baculosa are congeneric and that 

 I have been wrong in counting the latter a Phyllacanthus. 

 Since as already shown the name Stephanocidaris must be 

 abandoned, I follow Doderlein in using Prionocidaris, of which 

 P. pistillaris {—baculosa) is the type, for the group I have 

 hitherto called Stephanocidaris, the diagnosis being modified 

 to permit the inclusion of baculosa. Thirty-four specimens. 



Locs. — Off Eraser Island, Queensland. 



