96 A. OKA. 



" linvor," and the free end " upper," the side on which the anas opens 

 "nnal,' and the side opposite the anus "oral." 



The organs that constitute the Polyzoan hody may he classified 

 in the folio wi no- way. 



A. Organs for the preservation of the polyzobids 

 or the colony. 



1. Dermal System, consisting of the ectocyst and the endocyst. 



2. Digestive System, consisting of the epistome, the oesophagus, 



the stomach, and the intestine. 



3. Tentacles. 



4. Excretory Organs (?), consisting of two short ciliated tiihes. 



5. Muscular System, consisting of five groups of muscles. 



6. Nervous System, consistino- of a o-anoflion with two arms 



f >r the lophophore. 



B. Organs for the Preservation of the species. 



7. Ovary and Testis. 



8. Funiculus, in which the statoblasts are developed. 



9. The part of the endocyst that prc^duces buds. 



1. Dermal System. 



The integinnent of Polyzoa consists of two layers, quite different 

 in their nature, the outer "ectocyst" and the inner "endocyst" (see 

 fig. 4). The latter is not everywhere covered by the f n'mer, but is 

 exposed on the polypides. 



The ectocyst is gelatinous in this species. It fills up the space 

 between the branches of the cœnœcial endocyst, whereas in Pect, 

 magnifica, Leidy, there is no ectocyst between them. In this respect 



