18 HAWAIIAN AND OTHER PACIFIC ECHINI. 



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

 This tendency has been increased by confusing Phyllacanthus annulifera with 

 S. hispinosa, and as the former does not have a specially peculiar abactinal 

 system, it is not strange that the characteristic feature of Stephanocidaris 

 has been misunderstood. Tlie Hawaiian specimens not only show clearly 

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

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

 radioles (PI. 12^, figs. 10-13)^ a character we have observed in no other 

 cidarid except Acanlhocidaris hastigera (q. v.). 



Stephanocidaris bispinosa A. Ag. 



Cidarites bispinosa Lamarck, 1816, Anira. s. Vert. Ill, p. 57. 

 Stephanocidaris bispinosa A. Ag. 1872, Rev. Ech., Pt. I, p. 160. 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 species from Hawaii 

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

 pedicellaria? 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 large globiferous pedi- 

 cel la ria at all ; it appears to be a large example of a small globiferous 

 pedicellaria of a Phyllacanthus, and probably F. annuUfcra. 



Stephanocidaris hawaiiensis A. Ag. and Clark. 



Plates 4, figs. QO-23 ; 12^ figs. 12,13; 24; 25; 26, figs. 7-^. 



A large series of this species was collected by the " Albatross." var^'ing 

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

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

 actinal 18 mm., and tlu* longest priiuary radicles are 87 mm. long; there are 

 eight and eight large interaiubulacMal tubercles. In a specimen 33 mm. in 



» Ingolf Kchinoidi'a, 1!»0:^ Pt. I. V\. X, tig. 17. 



