THE MORPHOLOGY OF THK CHKILOSTOMATA. 263 



On the Morphology of the Cheilostomata. 



By 



Sidney F. llariiicr, Sc.D., F.K.S., 



Fellow of King's College, Cambridge ; Superintendent of the University 

 Museum of Zoology. 



With Plates 15—18. 



The observations on which the present paper is based were 

 commenced with the examination of a Flustra-like Oheilo- 

 stome, found at Port Jackson by Mr. T. Whitelegge, who 

 sent it to me for description, believing it to belong to a new 

 genus. Although exhibiting several remarkable features, I 

 think it may be placed in Euthyris, Hincks, and I propose 

 for it the name E. clathrata, in allusion to the bars which 

 support its " frontal wall." The species possesses a large 

 "compensation-sac/' a name which is due to JuUieu 

 (1888, 1), although the structure had to some extent been 

 described by Busk and Waters. Jullien's results have usually 

 been discredited by later writers. The study of a number 

 of Cheilostoniatous genera has, however, not only led 

 me to confirm the accuracy of Jullien's statements, but 

 has resulted in various conclusions which I believe to be of 

 importance for the proper understanding of the Cheilostomata. 

 A summary of my principal results has been communicated 

 to the Cambridge Philosophical Society (1901). 



The present paper is divided into the following parts : 

 I. Methods employed. 

 11. List of the species specially studied. 



