PIGMENTATION OF A POLYCLAD. 729 



References. 



Crozier, W. J. 



1916. Some indicators from animal tissues. Jour. Biol. Chem., 

 vol. 24, p. 443-445. 

 Gamble, F. W. 



1901. Flatworms and Mesozoa. The Cambridge Natural 



History, vol. 2, p. 1-96, 47 fig. London. 

 Gamble, F. W. 



1910. The relation between light and pigment formation in 

 Crenilabrus and Hippolyte. Quart. Jour. Micros. Sci., 

 vol. 55, p. 541-583, 1 pL 

 Gamble, F. W., and Keeble, F. W. 



1900. Hippolyte varians: a study of colour-change. Quart. 

 Jour. Micros. Sci., vol. 43, p. .589-698, 5 pi. 

 Potts, F. A. 



1915. The fauna associated with the crinoids of a tropical coral 

 reef: with especial reference to its color variations. 

 Publ. Carnegie Instn. Washington, No. 212, p. 73-96, 

 7 fig., 1 pi. 

 Van Name, W. G. 



1902. The ascidians of the Bermuda Islands. Trans. Conn. 



Acad. Arts and Sci., vol. 11, p. 325-412, 19 pi. 

 Verrill, A. E. 



1900. Additions to the turbellaria, nemertina, and annelida of 



the Bermudas. Trans. Conn. Acad. Arts and Sci., 

 vol. 10, p. 595-672, 1 pi. 

 Verrill, A. E. 



1901. Additions to the fauna of the Bermudas from the Yale 



expedition of 1901, with notes on other species. Trans. 

 Conn. Acad. Arts, and Sci., vol. 11, p. 15-62, 9 pi. 



