CERATOMYXA ACADIENSIS. 553 



II. Diagnosis of Ceratomyxa acadiensis, n. sp. 



Myxosporidium, typically club shaped, with a long tail (PI. Ill, 

 Figs. 42, 45, 50), often many times the length of the thicker part of 

 the body (PI. Ill, Fig. 50), but remarkably variable in shape (PI. Ill, 

 Figs. 41, 43, 44, 47, 48, 49). Large individuals may be irregularly 

 stellate (PI. Ill, 48). The pseudopodia often show a rigidity, as if 

 possessing an endoplasmic axis. Certain of the pseudopodia may show 

 clumps of protoplasm along their length, the clumps being connected 

 by thin hyaline filaments of ectoplasm (PI. Ill, Fig. 49). Division 

 into ectoplasm and endoplasm, though not always clear, is often to be 

 made out in the anterior region. In the parasite of Urophycis chuss 

 the myxosporidia were very often found attached in large numbers 

 to the myxosporidium of an undetermined species, described by the 

 author in a previous paper (Mavor, : 15). The examination of detached 

 individuals showed the connection to be brought about by short pseu- 

 dopodia at the anterior end. In the parasite of Zoarces angularis the 

 attachment is probably to the epithelium of the gall bladder, as the 

 fine pseudopodia are present, but the undetermined myxosporidian 

 present in U. chuss seems to be absent. In the parasite of Pseudo- 

 pleuronectes americanus no attachment has been observed. The 

 dimensions of a typical myxosporidium of the species are : 



Length, excluding tail 12-25 /x 



Width . 10-20 M 



Tail up to 60 /x 



Sporc,^ having the form typical for the genus, but very wide, short, 

 and slightly compressed dorso-ventrally, with very long fine lateral 

 filaments (Fig. A). Polar capsules spherical. Polar filaments not 

 visible in the fresh state, but extruded in either concentrated sulphuric 

 acid or a solution of iodine in potassic iodide. The average measure- 

 ments of spores are as follows : 



Length — sutural axis 7- 8 /u 



Width — bivalve axis 40- 50 ^l 



Diameter of polar capsule 3- 4 /i 



Length of lateral filaments 250-300 n 



Length of extruded polar filament 70 ^ 



Occurrence: (1) in the gall bladder of Urophycis chuss on the coast 

 of New Brunswick, Canada. Here the myxosporidium is usually 



2 A more detailed description of the spore will be found on page 566. 



