INTRODUCTION. CXXXV 



grounds on wliicli they have hitherto given their adhesion 

 to Ehreuberg. 



Note on the Phosphorescence of the Polyzoa. 



Phosphorescence has been observed in several species. 

 In Membranipora membranacea Dr. Landsborough de- 

 scribes the light as being very beautiful ; when a speci- 

 men was shaken, it presented the appearance of a " sheet 

 of fire.^^ In Membranipora pilosa every cell showed a 

 brilliant little star ; the zoarium was like '' an illuminated 

 city.'^ Scrupocellaria reptans and Valkeria uva, form 

 cuscuta, are also phosphorescent species. We learn from 

 M. Velain* that a Bugula occurs in the island of St. Paul, 

 in small submarine grottos, which is of a deep azure-blue 

 colour and strikingly phosphorescent. When the water 

 containing it was agitated it showed the most brilliant 

 coloured lights, which changed with astonishing rapidity 

 from red to green, or to azure-blue. When the water 

 was left quiet the beautiful display ceased. 



Systematic Table. 



Subkingdoai MOLLUSCA. 



Branch ACEPHALA. 

 Class POLYZOA, J. V. Thompson. 



Bryozoa, Ehreuberg, &c. 

 OiLiOBRACHiATA, Farre. 

 Tentaculibranchia, E. Ray Lankester. 



Acephala with well-developed, separate, ciliated gill- 



* " La Faune des lies St. Paul et Amsterdam," Arch. Zool. experimen- 

 tale, 1877. 



