on the Polyzoa. 93 



all, but an integral part of the zooecium. Dr. Jullien, in the 

 passage quoted below, speaks of it as something absolutely 

 distinct from the zooecial structure ; but he must have for- 

 gotten the investigations of Salensky*, Vigelius t, and others, 

 and the conclusive evidence afforded as to its morphological 

 significance by the relation which has been demonstrated 

 between it and the " Pedicellina-cn\) " or " crown." A3 

 Vigelius has clearly shown, the Pedicellina-cup is not the 

 mere " equivalent of a polypide," but " the homologue of a 

 ' polypo-cystide,' of which the stalk constitutes an integral 

 part." He adds : — " In ahnlicher Weise habe ich audi den 

 Korperbau von Barentsia aufgefasst." It is quite unneces- 

 sary to repeat here the admirable demonstration of the homo- 

 logies upon which this interpretation of the Pedicelline struc- 

 ture is based, which we have from the authors to whom I 

 have just referred. Their writings are accessible to the 

 student of the Polyzoa. It may be added that Nitsche, who 

 adopted a somewhat different theoretic view of the Pedicelline 

 cup, was prepared to regard the peduncle (and also the stolon) 

 as homologous with the zooecium of the Ectoprocta. Long ago 

 Allman \ anticipated to some extent the conclusions of recent 

 investigators respecting the nature of the peduncle, regarding 

 it as homologous with the posterior part of the cell in the 

 unstalked forms of Polyzoa. His prevision is sustained by 

 the results of the later research. 



The genus Barentsia, then, is founded on distinctly zocecial 

 characters, and as representing an important modification of 

 the Pedicelline type lias every claim to a place in our system. 

 If its validity is challenged it must be on different grounds 

 from those on which Dr. Jullien relies. 



As I have remarked in a previous portion of this paper, 

 there is hardly any serious difference of opinion now as to the 

 true basis of the classification of the Polyzoa, although we 

 have not yet determined with certainty the most significant 

 elements of the zocecial structure, as indications of genetic 

 affinity. We have reached a stage, as it seems to me, in 

 which there is need not so much of large schemes of recon- 

 struction as of patient investigation and the quiet accumula- 

 tion of data, which sooner or later must open the way for us 

 to a true apprehension of the order of nature. Meanwhile 



* "Etudes sur les Bryozoaires Ectoproctes," par M. Salensky, Ann. d. 

 Sc. Nat. 6 e ser. Zool. t. v. (1877), article no. 3. 



f ' Die Bryozoen, gesaminelt wahrend der dritten u. vierten Polarfahrt 

 des Willem Barents, in den Jahren 1880 u. 81/ von Dr. W. J. Vigelius, 

 pp. 89, 90. 



\ ' Freshwater Polyzoa,' p. 22. 



