92 Rev. T. Ilincks's Critical Notes 



Dr. Pergens has recently published an important paper* 

 containing the results of his anatomical and developmental 

 studies at the Zoological Station, Naples. He has had the 

 opportunity of examining a large number of species with all 

 the modern aids and appliances, and the paper is a valuable 

 contribution to our knowledge of the Polyzoa. We are 

 promised a continuation of it, which will be awaited with 

 much interest. So far the results obtained do not appear to 

 throw much new light on systematic questions ; but if the 

 observations recorded may be trusted, and they have evidently 

 been made under the most favourable circumstances, with all 

 care and full command of the newer methods of research, they 

 will exclude several of Dr. Jullien's interpretations of struc- 

 ture, and notably his view of the nature and origin of the 

 so-called pores in the cell-wall, which plays an important 

 part in his proposed classification. 



It would be impossible to examine the details of this classi- 

 fication within the limits of the present paper ; but in the 

 second section of it (on the Cribrilinidce) I shall refer to the 

 conception of the systematic significance of the zocecial front- 

 wall, on which it is largely founded. 



I pass on to consider briefly Dr. Jullien's strictures on 

 another case of supposed departure from the true principle of 

 zocecial classification. Some years since I instituted the 

 genus Barentsia for the reception of a Pedicelline form, cha- 

 racterized by the concentration of muscular tissue at the base 

 of the peduncle, as in the Pedicellina gracilis, Sars. Dr. 

 Jullien contends that this genus is founded on zoarial and not, 

 as it should be, on zocecial characters, and has therefore no 

 claim to acceptance. Accordingly he disallows it, and restores 

 the species which have been ranged under it to Pedicellina f. 

 I venture to think that he has committed himself to a hasty 

 judgment in this case, which he will find it difficult to main- 

 tain. 



The distinctive character of the genus Barentsia is the 

 remarkable modification of the muscular apparatus and the 

 structural change in the peduncle which it involves. 



The question at issue turns on the interpretation which we 

 put upon the so-called " stem " or peduncle of the Pedicel- 

 linidce. In my view it is not an element of the zoarium at 



* " Untersuchungen an Seebryozoen," Zool. Anzeiger, nos. 317 u. 318 

 (1889). 



t " Aussi je n'admets pas la classification proposee parTh. Hinckspour 

 les Pedicellines : les genres en sont etablis non sur la forme de la zooecie 

 ni sur les caracteres zoceciaux, mais sur le pedicelle de la zooecie " (' Mis- 

 sion Sc. du Cap Horn,' p. 6). 



