CERATOMYXA ACADIENSIS. 



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Figure C. Ceratomyxa acadiensis, n. sp., abnormalities in spores and 

 their development, a and h, triradiate spores from the gall bladder of U. chuss; 

 c, myxosporidium containing two sporoblasts, one forming a normal spore, 

 the other forming a triradiate spore with three polar capsules, from the gall 

 bladder of P. americanus. DrawTi from fresh preparations. X 390 diameters. 



V. Summary. 



1. A new species of Ceratomyxa from the gall bladder of Urophycis 

 chuss, Zoarces angularis, and Pseudopleuronectes americanus is 

 described. 



2. The earliest stage of Ceratomyxa acadiensis n. sp., found in the 

 gall bladder, contains a single nucleus. 



3. By a heteropolar division of this single nucleus a trophic and a 

 propagative nucleus arise. 



4. The stage of the mj^xosporidium with four nuclei probably arises 

 by the division of the trophic nucleus to form two tropho-nuclei and 

 the division of the propagative nucleus to form two propagative nuclei. 



5. The origin of the sporoblasts by the coming together of cells 

 originally separate, as described by Awerinzew for Ceratomyxa dre- 

 panopsettae, is confirmed for C. acadiensis. 



6. The presence of valve-cells and capsulogenous cells is established 

 for C. acadiensis. 



7. The two germ-nuclei can be distinguished in the early stages 

 of spore-formation and until the spore is completely formed. 



