244 Bulletin Vanderbilt Marine Museum, Vol. VI 



tern, which on the abactinal surface is very variable, combina- 

 tion of grayish green on reddish brown, a pattern that blends 

 inconspicuously into the environment sought by these young star- 

 fishes in crannies and under stones. Their tube-feet are light 

 yellow in younger forms, but a much deeper yellow in the older 

 star-fishes, which are a brilliant cobalt blue dorsally. For colour 

 plate of the juvenile and adult forms, consult H. L. Clark, 1921, 

 pi. 9, fig. 1 and 2, and pi. 21, fig. 21 ; also Saville Kent, "The Great 

 Barrier Reef of Australia," p. 358, pi. 12, fig. 8, 1893. 



Dr. E. N. Harvey gives an excellent account of the chemistry 

 of the blue pigmentation of this species in the Yearbook, Carnegie 

 Institute, Washington, No. 13, 1915, pp. 204-205. 



Technical description : The "Alva" series of this species, 

 one of which is figured, are all of medium size or very young. 

 Linckia laevigata is seldom subject to autotomous division, conse- 

 quently it is more regularly stellate than L. guildingii, being usual- 

 ly five-rayed, the arms being short, moderately stout, distally 

 rounded rather bluntly. R=80 mm., r=: 15 mm., average width 

 of arm 14 mm. Abactinal plates thick, frequently very convex, 

 polygonal, close together, with the papular areas apparently larger 

 than the plates, pores 3 to 6 ; with a median radial area in which 

 the papular areas appear to be lacking. The entire body is cov- 

 ered by a coarse granulation on the actinal surface ; these granu- 

 lations extend upon the sides of the ambulacral grooves, in a verti- 

 cal series of one to two fine granules wide, separating the furrow 

 spines, as shown in pi. 76, fig. B. The jaw angle and jaw teeth 

 are as shown in fig. A. There is normally one madreporic body 

 in this species, of the pattern figured, pi. 76, fig. C. Rarely two 

 to four madrepores per specimen have been recorded. 



The "Alva" specimens, from five different archipelagoes, are 

 typical of the wide distribution this species attains. The four 

 specimens from Vitu Levu, Fiji Islands, one of which is figured 

 on plates 74, 75 and 76, are of the small, stout form and measure : 



Median width 



R br. of arm 



A 85 16 20 



B 90 21 18 



C 88 18 19 



D 98 20 20 



All measurements are in millimeters. 



