48 bulletin: museum of comparative zoology. 



64, 67, 73, 6S, 71, 69, 72, 40, 42, 71, 66, 44, 75, 71, 72, 45, 66. Of the 25 rays, 

 one is 75 mm., one is 71, one is 73, three are 72, three are 71, one is 70, two are 

 69, two are 68, one is 67, two are 66, one is 65, one is 64, one is 57, one is 51, 

 one is 45, one is 44, one is 42, and one is 40 mm. long. Besides this diversity in 

 length, it is not an easy matter to s«.y just what proportion of the ray is free, for, 

 while of one ray 70 per cent may be free on one side and 65 on the other, another 

 ray may be only 50 per cent free on each side. To determine the point satisfac- 

 torily four or five of the longest rays should be measured, the measurements added 

 together and divided by four or five, as the case may be, the quotient being the 

 average R. Then measure the free portion on each side, add, and divide by eight 

 (or ten), the quotient being the average free portion. Dividing this by the aver- 

 age R gives the percentage of ray that is free. Adopting this plan for one of the 

 best specimens of multiradiatus, we get these figures : — 



83 + 83 + 82 + 76 + 80 = 404 mm. -f- 5 = 80.8 mm. = R. 

 50 + 51 + 50 -f 53 + 46 + 44 + 47 + 48 + 46 + 45 = 480 mm. -M0 = 48 mm. 

 = free portion. 



48 — 80.8 = .59 /. 59 per cent of ray is free. 



With the other five species of Heliaster it is not necessary to go to such trouble, 

 as all the rays are, in normal specimens, of approximately the same length. — 

 The specimens of multiradiatus from Chatham Island are notable for the large 

 abactinal spines, which are as heavy as in most specimens of kubiniji. One of 

 the specimens is further remarkable for the fact that although very large (11 = 

 100 mm.) there are only 15 developed rays and two of these are very small; there 

 is also a very rudimentary ray 6 mm. long, at one point on the abactinal surface. 

 Careful examination shows that this individual was at some time badly injured, 

 nearly bisected in fact, and has only imperfectly made up its loss. 



Material examined : — 



3 specimens. Albemarle Island. Leland Stanford Jr. Univ. collection. 



5 " Charles " M. C. Z. 



2 " Chatham " U. S. N. M. 



I specimen Albemarle " M. C. Z. 



II specimens. 3 localities. 



Heliaster kubiniji Xantus. 



Plate 4, Fig. 3 ; Plate 5, Fig. 3 ; Plate 6, Fig. 1 : Plate 7, Figs. 8-10 ; Plate 8, 



Figs. 1-6. 



Heliaster kubiniji Xantus, 1860. 

 Heliaster Kubiniji Verrill, 1867 

 Heliaster Kubinjii Liitken, 1871. 

 Asterias Kubinjyi Liitken, 1872. 

 Heliaster Kubingii Rathbun, 1887. 

 Heliaster Kubinijii Ives, 1889. 



Description. — Rays 21-28, averaging (90 adults) 23; about 47 (40-55) per cent 

 of ray free. R =60-107 mm.; r = 30-60 mm. Breadth of ray at base, 6.5-15 



