244 SOME MINUTE ANIMAL PARASITES 



shark, Galeus canis, shows numerous forms of tro- 

 phozoites, varying from subspherical to most extra- 

 ordinarily irregular bodies. The spores of some 

 species are prolonged laterally and form long horns 

 (Fig. 44, c), while in others no such appendages are 

 present. Wherever the spores occur, their extreme 

 fragility is a matter of comment. Sometimes they 

 attain a breadth of 32 /JL and a length of 6 /*. Their 

 polar capsules are adjacent to one another, but on 

 opposite sides of the valvular suture (Fig. 44, d). 



FIG. 44 CERATOMYXA: SPORE FROM BILE OP GALEUS CANIS 

 a, Sporoplasm ; &, pole capsule ; c, horns of spore ; d, suture. In 

 this species the two halves of the spore contain unequal 

 quantities of sporoplasm 



Sometimes the 'sporoplasm is unsymmetrically ar- 

 ranged. Such is the case with the spores of a new 

 species of Ceratomyxa (Fig. 44, a) occurring in the 

 gall-bladder of Galeus canis, though symmetry occurs 

 in the forms found in Crenilabrus, the gold sinny, 

 and Labrus, the wrasse. The wrasses we have 

 examined in North France and in England do not 

 seem to be parasitized, though they are often re- 

 ported to be so in South France. While the 

 parasite was formerly considered to be harmless, this 

 is now known to be an erroneous opinion, the para- 



