78 ILLINOIS BIOLOGICAL MONOGRAPHS [316 



CERATOMYXA AMORPHA Davis 

 [Fig. 64] 

 1917 Ceratomyxa amorpha Davis 1917 : 228 



Habitat: Gall-bladder of Synodus foetans; Beaufort. 



Vegetative form: Rounded or irregular in shape, with short lobose 

 pseudopodia; not pyriform; slowly ameboid. Body colorless. Ectoplasm 

 well developed, forming a distinct layer; transparent, finely granular. 

 Endoplasm granular, with large numbers of small fat globules scattered 

 through it or aggregated into one or two large clumps (difference between 

 the present form and C. agglomerata). Disporous. 



Spore: Asymmetrical; crescent-shaped; valves short, conical, some- 

 what compressed. One valve distinctly smaller and more conical than the 

 other. Sutural ridge perpendicular to longitudmal axis. Polar capsules 

 large, opening at some distance from the anterior side. Coiled polar 

 filaments distinct. Sporoplasm granular, asymmetrically situated, being 

 chiefly confined to smaller valve. Dimensions: breadth 27ju, sutural 

 diameter 11/i, diameter of polar capsules 4/x. 



CERATOMYXA MONOSPORA Davis 



[Figs. 65 to 67] 



1917 Ceratomyxa monospora Davis 1917 : 228-229 



Habitat: Ga.\\-h\a,dder oi Peprilus alepidoius; Beaufort. Abundantly 

 present in June, much less in July, being entirely absent in the bladder at 

 the end of the month. 



Vegetative form: Pyriform, with a slender posterior process and one to 

 several filiform pseudopodia at anterior end. Body colorless and trans- 

 parent. Movements very slow. No clear differentiation between ecto- 

 plasm and endoplasm, the entire body being composed of a clear, finely 

 granular protoplasm. Fat globules more abundant in larger mdividual, 

 which are aggregated into small clumps. Size of vegetative trophozoites 

 up to 24ju in length and 15/x in width. Monosporous form much smaller 

 than disporous. Monosporous and disporous. Nearly entire substance 

 of trophozoite is used up in spore formation. 



Spore: Crescent-shaped. Valves cylindrical, tapering toward the end, 

 which is rounded and compressed. Curvature of valves varies. One 

 valve is more attenuated than the other. Sutural ridge perpendicular to 

 the longest diameter. Polar capsules large. Sporoplasm usually asym- 

 metrically situated. Dimensions: breadth 18 to 25;x, sutural diameter 

 5 to 6/i, diameter of polar capsules 3ju. 



Remarks: This species is evidently very close to C. pallida Thel. 

 Similar form was found in Prionotus evolans (gall-bladder), which showed 

 somewhat larger trophozoites and spores than C. monospora. 



