ON THE NErHEIUlU.M OE rHYLACTOLAEMAT(>US I'OLYZOA. 83 



two ligures, aiid the remarks of Hiucks^ and Siuitt," both of whom do not 

 go beyond confirming the observation of the first. Farre found in Membnc- 

 iilponc 'pilosa and Alr[/onidiu»i (jelatiiiosuni a bottle shaped organ, ciliated 

 internall}^ situated between the tentacles and terminating in a ciliated funnel. 

 Contrary to all the segmental organs, it lies floating in water outside the 

 body of the polypide and communicates with the body-cavity only by its 

 lower extremity. x\s this organ is, according to Farre's figures, very dif- 

 ferent from the one I have described above, it is impossible at present to 

 discuss whether the two organs are homoloii^ous or not. Joliet who searched 

 specially for this organ in one of the species mentioned above, namely Mem- 

 hraiiipora pilosa, i^ixiiie only io negoXxve results. I could not find any such 

 organ, too, in various species of ScrapoceUarui, Btignia, AinatJiia, Uetepora, 

 kc, although as I did not use high powers I am not sure whether the 

 animals really had no nephridia internally. As already proved by Harmer, 

 the leucocytes and the cells of the peritoneal lining of marine Polyzoa take 

 up foreign substances, and it seems very probable that there exists some 

 passage for the exit of these cells. Perhaps the semilunar pore of Micro- 

 porclla, discovered ])y Pergens" might serve for the purpose. At any rate, a 

 minute investigation of marine Polyzoa with regards to this point is very 

 much to be wished. 



Nephridium of Eadoproctoiis Folyzoa. We ov*-e our knowledge on the 

 nephridium of Endoproctas Polyzoa principally to Hatschek* and Joliet.^ 

 In his admirable paper " tjber die Embryonalentwicklung and knospung 

 der Pedicellina " Hatschek describes a fine ciliated canal situated in the 

 body-cavity, in the neighbourhood of the ganghon, with one end opening 

 exteriorly, but the mode of termination at both ends could not be determined 

 positively. He says : " Trofcz Anwendung von stiirkeren Yergrosserung 



1. Notes on British Zoophytes with descriptions of some new six'cies. Ann. and Mag. of 

 Xat. Hist. 2nd ser. VIII. 1851. 



2. Kritisk. forteekning ofver skand. Hafs-Bryoz. Oeversigt af K. A'etensk Akad. VI. 



3. Zool. Anz. XII. 1889. 



4. tJber die Embryonalentwicklung und knospung der Pedicellina. Zeitschx". f. M'iss. Zool 

 XXIX. 



5. Organe segmentaire des Bryozoaires endoproctes. Arch de Zool. expcr. VIII, 



