40 GEORGE OSSIAN SARS. 



sliglitly crenulated at the edgesj representing the tentacular 

 arms ; the stalk (h), which represents the contractile cord^ 

 has lengthened itself considerably (see fig. 9), and its 

 anterior part forms a strong enlargement, marked with 

 evident traces of the spots of dark violet colouring- 

 matter peculiar to the adult animal. The real body was, as 

 stated, still very slightly developed, and appeared only as a 

 small rounded part projecting dorsally between that enlarged 

 pai't of the stalk and the basis of the tentacular arms ; on the 

 ventral side, or that which turned towards the concave sur- 

 face of the scutiform plate, it was in the middle, and to a 

 small extent united to the same by gi*owth ; and behind this 

 union there appeared already an evident incurvation or inci- 

 sion in the body of the polypide as the first indication of the 

 buccal orifice. That the large scutiform plate is the homo- 

 logon of the buccal shield in the fully developed polypide is 

 sufficiently evident, both from its position relatively to the 

 animaFs body and from its shape. Allman has also recog- 

 nised this ; however, when he assimilates this plate in the 

 Khabdopleura-buds with the mantle lobes of the Lamelli- 

 branchiata, the notion seems to me very hazardous and diffi- 

 cult to establish. In any case, the early appearance and 

 enormous development of this part in the buds of the Rhab- 

 dopleura are extremely remarkable. 



Allman has — guided especially by the mode of develop- 

 ment in the Rhabdopleiira — come to the conclusion that the 

 Polyzoa are not, as was formerly imagined, most nearly re- 

 lated to the Brachiopods, but to the Lamellibranchiata, and 

 gives, 1. c, some schematic figures, in order to represent 

 more evidently the agreement of the Rhabdopleura-buds with 

 a Lamellibranch. Allman, however, presupposes, as taken 

 for granted, that the Rhabdopleura is furnished Avith an en- 

 docyst of the same nature as the other Polyzoa, which, as 

 above stated, is not the case, as also his conception of the 

 buccal shield seems to be inaccurate. 



As will be seen in the sequel, my father has acquired a 

 very different notion with regard to the relationship of the 

 Polyzoa; for — guided by the organization of their lowest 

 representative, the Rhabdopleura — he has arrived at the sur- 

 prising conclusion that the Polyzoa in all probability have 

 taken their orgin from the Coelenterates, namely, the 

 Hydrozoa. 



Like Allman, I sometimes found in the middle of the 

 stem of the polyzoarium individual chambers, which, with- 

 out containing any bud in process of formation, were 

 quite closed and not continued into any cell. The interior 



