REPORT ON PHORONIS BUSKII. 



27 



with the collar of Cephalodiscus. Its muscular and circulatory systems arc more 

 highly developed than in any of those indicated. It differs also in the absence of 

 reproduction by budding. 



While it is difficult in the ease of such peculiar types as Phoronis to draw parallel 

 features with any group with which they may be associated, yet in the present state of 

 our knowledge there does not appear to be any other division with which Phoronis 

 more closely agrees than with the forms above mentioned, and especially with the 

 Aspidophorous group of the Polyzoa. Phoronis, indeed, is one of those forms which 

 cannot all at once be placed in close relationship with known groups, and the true 

 position of which, perhaps, cannot yet be accurately fixed. At present, however, I am 

 inclined to coincide in the view of Professor Lankester, that it may conveniently be 

 classified as an aberrant Polyzoon. 



CONTENTS. 



Introduction, 



Anatomical Description, 



Tube, 



External Form, 



Body-WaU, 



Tentacles, 



Body-Cavity, 



Digestive System, . 



Circulatory Organs, 



Nervous System, . 



Nephridia, 



Reproductive Organs and Development, 



Homologies, 



5 

 6 



7 

 11 

 U 



15 



17 

 18 

 21 

 22 

 2i 



