LAG EN I Dl ALES 1007 



irregular hyphae which are sparingly septate, 5.4-12.6 \x thick. Proto- 

 plasm with a pale whitish gleam and numerous oil bodies, becoming 

 coarsely granular just before spore formation. In the process of spore 

 formation and discharge the end of a thread becomes applied to the 

 inner egg wall and swells to form a clavate structure up to 30 u thick. 

 The part in contact with the wall forms a narrow tube which grows 

 through the wall and immediately thickens and elongates to form a large 

 tube 1 1-29 ■ 25-70 u. The tip of the tube gelatinizes and protoplasm 

 flows out from the mycelium to collect into a spherical or subspherical 

 undifferentiated mass surrounded by a thick gelatinous envelope. 

 Protoplasmic mass up to 100 [j. thick. Spores formed as in Pythium from 

 this mass of protoplasm, and becoming very active within the gelatinous 

 layer before discharge. When mature breaking through the outer gelat- 

 inous membrane or vesicle and swimming sluggishly away. Vesicle 

 persistent. Spores pointed at the front end and rounded behind with a 

 diagonal groove which arises near the front end and extends backward 

 over the rounded end. Cilia arising from this groove and one extending 

 forward, the other backward while swimming. Zoospores about 9.6 

 12.6 (jl, with several oil globules one of which is distinctly larger than 

 the others. Encysted spores oblong or subglobose, 10 11.3 a; mono- 

 planetic. Resting bodies formed only after the crab eggs begin to dis- 

 integrate, apparently formed asexually in the threads, spherical, sub- 

 spherical or oval, 18-30 u thick, usually about 25 [jl thick, wall up to 3 a 

 thick, containing pale whitish protoplasm and an eccentric mass of oil 

 bodies; germination not observed" (Couch, be. cit.). 



Parasitic on eggs and newly hatched young of the blue crab Calli- 

 nectes, United States. 



The disease caused by this unique marine species has been the subject 

 of a comprehensive study by Rogers-Talbert (1948). The fungus is a 

 peripheral parasite of the egg masses of the blue crab, and the eggs are 

 susceptible to infection in all stages of their development. The infected 

 areas are brown or gray, depending upon the age of the eggs. While the 

 fungus spread rapidly over the egg mass, it appeared to penetrate it 

 slowly, usually going no deeper than 3 mm. This peripheral infection 

 did not retard the development of the eggs in the interior of the sponge. 

 Approximately 25 per cent of the eggs of a heavily diseased mass were 



