36 



THE AMERICAN NATURALIST [Vol. XLIX 



tenuispina has 7 rays before it undergoes autotomy, that 

 it divides into 3-ray and 4-ray portions, and that each of 

 these parts regenerates 4 rays. 



5. Eegenerating rays tend to appear in bilaterally dis- 

 posed pairs, as regards size. 



6. There is no evidence that self-division occurs often 

 in the life of individuals, though possibly it does. 



7. New rays may be added at any point on the disc. 



8. The number of madreporites varies from 1 to 5, and 

 is to some extent correlated with the number of rays ; it is 

 not correlated with the size of the animal. 



9. Double or triple madreporites occur in about 5 per 

 cent, of the individuals. 



Clark, H. L. 1901. Bermudan Echinoderms. A Report on Observations 

 and Collections Made in 1899. Proc. Boston Soc. Nat. Hist., 

 Vol. 29, No. 16, pp. 339-345. 

 1907. The Starfishes of the Genus Heliaster. Bull. Mus. Comp. Zodl., 



Vol. 51, pp. 23-76, 8 pis. 

 1913. Autotomy in LincMa. Zool. Am., Bd. 42, No. 4, pp. 156-159. 

 Davenport, G. C. 1901. Variation in the Madreporic Body and Stone 

 Canal of Asterias vulgaris. Science, N. S., Vol. 13, pp. 374- 

 375. 



King, Helen D. 1898. Regeneration in Asterias vulgaris. Arch. f. Entw.- 



mech., Bd. 7, Heft 2-3, pp. 351-363. 

 1900. Further Studies on Regeneration in Asterias vulgaris. Arch. 



f. Entw.-mech., Bd. 9, Heft 4, pp. 724-737. 

 Ludwig, H. 1897. Die Seesterne des Mittelmeeres. Fauna u. Flora d. 



Golfes v. Neapel, Monogr. 24 x + 491 p., 12 Fig. and 12 Taf. 

 M'Intosh, D. C. 1907. Meristic Variation in the Common Sun-Star (So- 



laster papposus). Proc. Boy. Phys. Soc. Edinburgh, Vol. 17, 



pp. 75-78. 



Mark, E. L. 1905. The Bermuda Islands and the Bermuda Biological 



Station for Research. Proc. Amer. Assoc. Adv. Sci., Vol. 54, 



pp. 471-501, 16 pis. 

 Martens, E.von. 1866. TJeber ostasiatische Echinodermen. Arch. f. 



Naturg., Jahrg. 32, Bd. 1, pp. 57-88. 

 Monks, Sarah P. 1904. Variability and Autotomy of Phatariai [Linckia]. 



Proc. Phila. Acad. Nat. Sci., Vol. 56, pp. 596-600. 

 Ritter, W. E., and Crocker, G. R. 1900. Multiplication of Rays and Bi- 



anthoides (Stimpson). (Papers from the Harriman Alaska 

 Expedition, III.) Proc. Wash. Acad. Sci., Vol 2, pp. 247-274, 

 pi. 13, 14. 



i "Phataria" is an error, as pointed out by Clark (1913). 



