18 HAWAIIAN AND OTHER PACIFIC ECHINI. 



rare, and recent writers have been disposed to ignore the genus altogether. 

 This tendency h.as been increased by confusing Phyllacanfkiis annnlifera witli 

 S. hkplnosa, and as the former does not have a speciahy peculiar abactinal 

 sj'stein, it is not strange that the characteristic feature of Stephanocidaris 

 has been misunderstood. The Hawaiian specimens not only show clearly 

 the remarkable abactinal system, but enable us to call attention to another 

 feature of the genus, found in tlie peculiar "capping" of tlie actinal primary 

 radioles (PI. 12'', figs. 10-lJ), a character we have observed in no other 

 cidarid except AcantJmcidaris liastujcva (q. v.). 



Stephanocidaris bispinosa A. Ag. 



Cidarites bispinosa Lamaruk, 181G, Aniiu. s. Vert. Ill, ]). 57. 

 Stephanocidaris bispinosa A. Ag. 1872, Rev. Ech., Pt. I, p. 1(;0. PI. I/, 1. 



Plate 12^ figs. 10, 11. 



The peculiar "capping" of the actinal primary spines is a striking 

 character of this handsome species, and is clearly shown in the figures given. 

 It will also be noticed that the abactinal side of these spines is marked 

 with roundish white spots, and it is interesting to see that the same feature 

 is present to an even greater degree in the new s})ecies from Hawaii 

 (PI. 12"', fig. i.'). We have been unable to find any large globiferous 

 pedicellariaj in the single available specimen of this species, but it is safe 

 to say that the figure given by Mortensen^ is not that of a Stephanocidaris 

 pedicellaria, if, indeed, it represents the valve of a hmjc globiferous pedi- 

 cellaria at all ; it appears to be a large example of a ayiiall globiferous 

 pedicellaria of a Phyllacanthus, and probably P. annuliferu. 



Stephanocidaris havraiiensis A. Ag. and Clark. 

 Plates 4, figs. ^0-23; 12^ figs. 12,13; 24; 25; 26, figs. 1-.',. 



A large series of this species was collected by the " Albatross," varying 

 in size from 41 mm. to G mm. in diameter. In a specimen of 41 mm. 

 diameter the abactinal system measures 20 mm., the anal 11 mm., and the 

 actinal 18 mm., and the longest pi'imnry radioles arc S7 mm. long ; tliere are 

 eight and eight large interambulacral tul)er('les. In a specimen oo mm. in 



1 Iiigolf Kohinoidea, !!»():!, I't. I, PI. X, ti-. 17. 



