REPORT ON CEPHALODISCUS DODECALOPHTJS. 35 



a much more spacious chamber divided by various mesenteries. In Balanoglossus this 

 chamber posteriorly is inconspicuous in the adult. The condition again in the Ento- 

 proctous Polyzoa {e.g., Loxosoma) considerably diverges, for no body-cavity exists; while 

 in the Phylactolsemata it is present in the adult, and is lined by ciliated epithelium, such 

 not being the case in the body-cavity of the Gymnoltemata. 



It is an interesting fact that the Muscular System both in Cephalodiscus and Rhahdo- 

 'pleura is connected with the pedicle, if we may for the moment so term the soft 

 contractile stalk of the latter. In the former, however, it is much more largely developed 

 and is continued directly from the body-cavity ; whereas in Rhabdo2ileura it is wholly 

 external to that chamber, and is less distinctly differentiated on the surface of the axial 

 skeleton, which forms another feature of distinction in this form. If the funiculus of 

 one of the Eupolyzoa be disconnected from the digestive system and formed into an 

 external process in the line of the ordinary communication-plate, something similar in 

 structure and function to the pedicle in the Aspidophora will be made. As a rule in the 

 same group the retractor muscles of the body and lophophore arise from the peritoneal 

 lining. 



The funiculus of the Eupolyzoa, according to Haddon, is probably derived from the 

 irregular strands of funicular tissue which occur in the parent zooecium. It appears as a 

 thickish cord stretching from the fundus of the developing polypide 'to the base of the 

 zooecium. It is in direct communication with the brown body, directing " the developing 

 alimentary tract to that nutritive mass, thereby ensuring the better nutrition of the 

 growing bud." The bud is thus developed at a distance from the brown body, but 

 approaches it and extracts nutriment from it. This has been noted by other authors. 

 In Loxosoma the stem quite differs, since there is no communication with the body- 

 cavity. 



The present condition of our knowledge of the Reproductive Organs, both in Cephalo- 

 discus and Rhahdopleura, is incomplete, so that a satisfactory comparison cannot be 

 made. The ova in the former are very large, but no male elements have been seen. In 

 Rhahdopleura the testis occurs as a long sac adjoining the intestine and even 

 projecting beyond the abdomen. It opens near the anus, and thus agrees with the 

 condition in Cephalodiscus and Phoronis, as well as offers certain resemblances to the 

 condition in the Entoproctous Polyzoa. The reproductive organs in Phoronis are 

 posterior in position, and both male and female elements are usually conspicuous. In 

 Balanoglossus these elements occur between the liver and the anterior part of the body. 



The early appearance of the ova in the young buds of the Eupolyzoa, for instance 

 Bugida Jlabellata, as noticed by Haddon, is worthy of mention. These ova are in close 

 relation to the wall of the digestive tract. The distinction of the Aspidophora from those 

 of the Eupolyzoa in which the ova of the parent pass ready-formed into buds is 

 marked. 



