264 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



concealed by foreign organisms and also by particles of mud. The 

 test and secondaries are a more grayish white. The naked test is 

 white. 



Another younger specimen with the apical disks not yet developed 

 was dredged by the author at the Kei Islands in 1922. 



Remarks. — This very fine species recalls through the character of 

 its primary spines Goniocidaris (Discocidaris) mikado, from which it 

 differs, however, very conspicuously in several important points, 

 especially in its spiny secondaries and very small and slender miliary 

 spines. It seems evident, however, that the two species are rather 

 closely related. On the other hand, the present species would appear 

 to have some relation also to the Petalocidaris group, with which it 

 agrees in having the secondary spines spiny at the base and in the 

 valves of the large globiferous pedicellariae being more or less dis- 

 tinctly prolonged into a narrow tube. It is hard to say which of the 

 characters are of the greater significance. I would, however, be 

 inclined to consider the character of the primary spines the more im- 

 portant, and therefore I refer this species to the subgenus Discocidaris 

 together with Japanese species mikado. 



Cyrtocidaris, 5 new subgenus 



Characters. — This new subgenus of Goniocidaris is distinguished by 

 its unusually long and slender pointed secondary spines, which are 

 smooth and flattened. The primary spines are long and slender, 

 rather strongly spinous, and more or less distinctly curved down- 

 ward. The oral primaries are very smooth, distinctly curved, and 

 in general rather conspicuous. 



Genotype. — The type of this new subgenus is Goniocidaris {Cyr- 

 tocidaris) tenuispina, new species, described below. 



Remarks. — It may be questioned whether it would not perhaps be 

 preferable to make this species the type of a separate genus instead 

 of merely a subgenus of Goniocidaris. But as in the great genus 

 Goniocidaris the secondary spines vary rather widely it seems to me 

 better to regard it only as a subgenus, even though the differences 

 separating it from the other species of Goniocidaris are really rather 

 striking. 



GONIOCIDARIS (CYRTOCIDARIS) TENUISPINA, new species 



Plate 57, figs. 1, 2; plate 58, fig. 1; plate 59, fig. 2; plate 61, figs. 6-8; plate 63, 

 fig. 5; plate 73, figs. 5, 6; plate 79, figs. 1-3 



Localities. — Station 5348; Palawan Passage; Point Tabonan bear- 

 ing S. 89° E., 33.5 miles distant (lat. 10° 57' 45" N., long. 118° 38' 

 15" E.); 685 meters; bottom temperature 13.56° C; coral sand; 

 December 27, 1908 (1 specimen, Cat. No. E. 1384, U.S.N.M.). 



'From Kvpr6s= curved. 



