318 OvK Paulsen. 



two or four cells are often seen lo be together and again dividing. 

 The cell-wall is rather thick, in some cases I have been able to see 

 a three-fold outline (fig. E); the outmost layer is very thin and in- 

 conspicuous, by treatment with chloriodide of zinc it disappears 

 but not with Eau de Janelle (a mucilage?) The wall itself is co- 

 loured brownish violet by chloriodide of zinc. In spite of eager 

 research it has not been possible to find other stages of this orga- 

 nism than those here mentioned and figured. 



The systematic position of this species, imperfectly known as it 

 is, must of course be uncertain. I refer it with some doubt to the 

 genus Apodiniiim Chatton (Comptes rendus Ac. sc. Paris 144. 1907, 

 p. 283, with figures. Se also: ibid. 143, Chatton: Les Blastodinides, 

 ordre nouveau des Dinoflagellés parasites.) The other Blastodinidae 

 described and figured b}' Chatton are far from being like our spe- 

 cies, but Apodinium mycetoides, a parasite upon Appendicalaria, 

 shows some features which call to mind A. Chaetoceratis. A. myce- 

 toides is fixed upon the host by a long stalk. Growing up and 

 dividing it has at first some resemblance to our species, being two- 

 celled and of about the same form, but it is only partly filled by 

 plasma, a great "lacune aqueuse" taking most of the room in the 

 two cells. Later on the distal cell ("blastocyte") divides again for- 

 ming many spores which again divide, and so a lot of small Gym- 

 nodinium-Vike spores are formed. The proximal blastocyte after a 

 rest divides, and the new distal cell forms a new^ generation of 

 spores, as described above. 



Of all this I have found no trace by Apodimu.mf?J Chaetoceratis. 

 As a whole this species may be called rather dubious. 



14-3—1911. 



