284 HAWAIIAN AND OTHER PACIFIC ECHINI. 



the largest specimen. The valves (PI. 93, fig. 7) are only about a millimeter 

 long and are strongly compressed. The triphyllous are rare and hard to find; 

 the valves are about .30 mm. long and .25 wide. The dumb-bell shaped spicules 

 in the globiferous pedicellarise are not peculiar. 



The ground color of the test is light drab, approaching white. In the smaller 

 specimens this is very distinctly marked with broad, horizontal bands of green. 

 There is such a band at or near the ambitus and one or two above it; there may 

 be one on the actinal surface. These bands may be either continuous or broken 

 at the poriferous areas. The abactinal system, excepting the periproct, is also 

 more or less green. In the largest specimen all these green markings are either 

 wanting or only faintly indicated. All of the smaller spines are white but the 

 primaries are more or less green. At the ambitus, each primary has a single, 

 broad, poorly defined band of green, leaving both base and tip white. Actinally 

 this band becomes broader and more or less clearly divided into two or three 

 narrower bands, the base and tip of the spine remaining white. Abactinally 

 the green coloration becomes more or less completely diffused throughout the 

 whole spine, though it is often most marked at the base. There is no hint of 

 red anywhere. 



The four specimens on which this species is based were received by the Mu- 

 seum of Comparative Zoology from the Godeffroy Museum in 1870, and are 

 labelled "Samoa." The largest is 106 mm. in diameter and 56 mm. high while 

 the smallest is only 40 mm. h. d. The latter and the next to the largest have the 

 green markings very deep and well defined. It is quite possible that this species 

 will prove to have the same relation to typical pileolus that the Florida form of 

 Lytechinus variegatus has to the typical form of that species, and if such proves 

 to be the case, then chloracanthus should rank only as a subspecies. In the 

 absence of connecting forms however it is preferable to give it full specific rank. 

 The occurrence of this green form of Toxopneustes at Samoa is interesting in 

 connection with the existence of a well-marked green variety of Mespilia among 

 the same islands (see p. 322). The latter however seems to occur with the usual 

 form, while so far as known typical pileolus does not occur at Samoa. 



