220 HAWAIIAN AND OTHER PACIFIC ECHINI. 



intermediate between the two latter. The sphceridia (PL 91, fig. 13) are some- 

 what elongated and a trifle angular; they occur on the lower secondary element 

 of most of the ambulacral plates. The calcareous spicules of the tube-feet are 

 large, irregular, fenestrated plates with an essentially smooth surface; they 

 occur in considerable numbers. 



The coloration of this species shows almost no variation and is very charac- 

 teristic. The test is violet, at least abactinally, deepest and most marked on the 

 genital plates which are, at least proximally, very close to violet no. 507 of 

 Klincksieck and Valette's Code; actinally the violet fades into a dingy white. 

 The primary spines are dull reddish (about no. 87 K. & V.) at base, but fade 

 into a clear greenish yellow (about no. 266 K. & V.) at tip. The small spines 

 are very light and the buccal membrane and periproct are pale bluish. These 

 colors are-taken from an alcoholic specimen, but they are not essentially modified 

 by drying. 



On first examination of the Hawaiian specimens, Mr. Agassiz and I were led 

 by the unbanded spines and the general features of the test to consider them 

 identical with the "Siboga" species, described by de Meijere as indica. A more 

 careful comparison of this material with the specimens of mirabilis, subsequently 

 received, together with a more critical examination of de Meijere's description 

 and figures showed that indica is quite distinct from any of the other species. 

 The characteristic differences have been set forth in the table above and do not 

 need to be repeated here, save to emphasize the fact that in indica the test and 

 spines are reddish flesh-color, the spines becoming whitish at the tip. The test 

 of de Meijere's specimen is recorded as 19 mm. in diameter and 12 mm. high, 

 which would indicate a much higher test than in hawaiiensis but as the photo- 

 graph is about 22 mm. by 11, the apparent difference is unimportant. Accord- 

 ing to de Meijere the actinostome in indica is as large as the abactinal system 

 and this may be a good specific character for in our specimens of hawaiiensis, 

 small and large alike, the actinostome is only three quarters as large as the 

 abactinal system. 



The "Albatross" took this species at the following stations: 



Station 3865. Off Mokuhooniki Islet, Pailolo Channel, Hawaiian Islands. 

 Bott. temp. 44.8-45. 256-283 fathoms. Fne. vol. s., r. 



Station 3879. Off Molokini Islet, south of Lanai, H. I. Bott. temp. 37.1. 

 923-1081 fathoms. Glob, oz., r. 



Station 3914. Off Diamond Head, Oahu, H. I. Bott. temp. 46? 289-292 

 fathoms. Gy. s., m. 



