54 hawaiia:^ and other pacific echini. 



the Cape of Good Hope, in 56 fathoms, and identified by Doderlein as Pat- 

 iersoni, but which is undoubtedly distinct from that species, and may be appro- 

 priately called phoinissa (=dark red); and S. cincta A. Ag. and CI., collected 

 by the "Albatross" in the northwestern Pacific, in 95-152 fathoms. (So 

 far as can be judged from de Meijere's brief description, the small Salenia 

 collected by the ''Siboga" in the Sulu Archipelago, in 290 fathoms, and 

 referred by him to Pattersoni, is probably cincta.) These three living species 

 are all notable for their handsome coloration, the abactinal system being pret- 

 tily ornamented, and the primary spines conspicuously banded or spotted 

 with some shade of red. They may be distinguished from each other as 

 follows : 



Actinal system, .40-.55 h. d.^ ; primaries rather slender, thickness commonly 

 much less than 5 per cent of length ; no red-brown pigment on test or 

 secondaries. 

 Abactinal system, .60-.70 h. d., light colored with plates outlined in deep 



violet ; primaries with 3-5 broad bands of bright red Pattersoni. 



Abactinal system, .55-.60 h. d., deep purplish ; primaries with 12-16 nar- 

 row bands of dull red cincta. 



Actinal system, .30-.35 h. d. ; primaries rather stout, thickness often 4-5 per 

 cent of length ; test and secondaries with red-brown pigment ; abac- 

 tinal system about .55 h. d., very dark ; primaries with 9 broad, brown- 

 red spots on upper surface plioinissa. 



In addition to these differences, it is interesting to note that Pattersoni 

 has both tridentate and quadridentate pedicellaria?, the latter with valves up 

 to 2 mm. long, while ^Aoi'm'ssa apparently lacks quadridentate, and the valves 

 of the tridentate are seldom half a millimeter in length. In cincta neither 

 tridentate nor quadridentate pedicellaria) have been found, and it would 

 seem that they are characteristically absent. In Doderlein's description of 

 the " Valdivia" specimen, he says there are 3 rows of secondary tubercles 

 in the ambulacra. It is impossible to tell from the illustrations given 

 whether this is really the case, or whether the "3" is not a misprint for 2. 

 If it is not a misprint, we have here another very important difference be- 

 tween j)h»inissa and Paticrsoni, for even the largest specimens of the latter 

 have only 2 scries of ambuhicral tubercles. 



' TluTO are two abbreviations used frequently in tlie following pages, h. d. and v. d. ; the former 

 rofcr.s to the horizontal, tho latter to the vertical diameter of the test. 



