ON THE EMBRYOLOGY OF THE ECTOPROCTA. 13 



a great part of the difficulty in the comparison between Repia- 

 chofF's larva and that of Alcyonidium would be removed if it could 

 be shown (as I suspect will be the case) 



(1) That E.epiacho£f's mantle-cavity (c.t in the figures) is 

 really the internal sac or sucker. 



(2) That the 'dorsal ciliated furrow' of the Bowerbankia larva 

 is the pyriform organ. 



In conclusion I may allude to Repiachoff's sta.tement (15) that 

 the brown body of the recently fixed larva is ciliated. It is 

 probably not very rash to assume that these cilia really belong to 

 the external surface of the larva involuted to the interior during 

 the process of fixation. 



List of memoirs referred to: 



1. Barrels, J. ; Recherches sur rEmbryologie des Bryozoaires ; Lille, 



1877. 



2. Mem. sur la Metamorphose des Bryozoaires ; Ann. des 



Sol. Nat. (Zool.), 6= Ser., T. ix, 1879—1880, No. 7. 



3. Embryogfinie des Bryozoaires ; Joum. de I'Anat. et de la 



Physiol., T. xviii, 1882, p. 124. 



4. Mem. sur la Metamorphose de quelques Bryozoaires; 



Ann. des Sci. Nat. (Zool.), 7= Ser., T. i, 1886, No. 1. 



5. Harmer, S. F.; On the Structure and Development of Loxosoma; 

 Quart. Journ. Micr. Sci., Vol. xxv, 1885, p. 261. 



6. On the Life- history of Pedicellina ; Quart. Journ. Micr. 



Sci., Vol. XXVII, 1887, p. 239. 



7. Hassall, A. H. ; Description of two new genera of Irish 



Zoophytes; Ann. and Mag. of Nat. Hist., Vol. vii, 1841, p. 

 484. 



8. Hincks, T. ; A History of the British Marine Polyzoa (two 



vols.); London, 1880. 



9. Joliet L. ; Cent, k I'hist. nat. des Bryozoaires des C6tes de 



France ; Arch, de Zool. Exp. et Gen., T. vi, 1877, p, 292. 



