108 ILLINOIS BIOLOGICAL MONOGRAPHS [346 



MYXIDIUM INCURVATUM Thelohan 

 [Figs. 241 to 251] 



Habitat: Gall-bladder of Nerophis aequoreus L., A^. annulatus, N. 

 lumbriciformis, Blennius pholis L., Callionymiis lyra L., Fundulus majalis, 

 Gambusia affinis, Hippocampus brevirostris, Mugil cephalus, Scorpaena 

 scrofa L., Syngnathus acus L., S. typhle; Roscoff, Concarneau, Marseille, 

 Banyuls, Napoli, Bergen, Monaco, Beaufort (July). 



Vegetative form: Thelohan describes as follows: Trophozoites usually 

 small, sometimes reaching a considerable size. Pseudopodia lobose. 

 Protoplasm pale and finely granular with refractive globules. Disporous. 

 According to Parisi and Davis rarely monosporous. Georgevitch observed 

 apparently the polysporous form. 



Parisi's form: ectoplasm hyaline, endoplasm granular. Monosporous 

 form 25/1 long. 



Davis's form: lobose pseudopodia, occasionally being drawn out into a 

 long process. Many trophozoites often cling together closely. Diameter 

 of rounded disporous forms about 13 to 15/1, that of monosporous forms 

 about 10 to ll/i. 



Spore: Thelohan's description is as follows: Irregular fusiform. Long- 

 est axis curved into S-form, both ends sharply pointed and directed toward 

 opposite directions. Polar capsule opening on opposite side of the spore, 

 in some spores the axis of the polar capsules being parallel to each other. 

 Dimensions: length 8 to 9m, breadth 4 to 5/t, length of polar filament 10 

 to IS/t. 



Parisi gave the following dimensions: length 10 to 12/i, breadth 5 to 

 6/t, length of polar capsule S/jl, length of polar filament 28/i. 



According to Georgevitch, young spores are not curved (Fig. 245). 



Davis's form; Polar filaments when extruded in HCl remained tightly 

 coiled. Dimensions: length 8 to 9/i, width 5 to 6ju, diameter of polar 

 capsule about 3/x. 



Remarks: As are shown in figures, Davis's form seems to be some- 

 what different from the European forms. 



