THE MYXOSPOEIDIA, OR PSOROSPERMS OP FlSHES. 281 



of coagulants, as an ii-regiilar, very low and biconcave-excavated 

 cylinder. Lutz could find no true nuclei, either before or after develop- 

 ment. Micrococcus-like corpuscles (similar to those in the ectoplasm, 

 see above) were present, but on account of their inconstancy, these must 

 be regarded as plasmatic secretions. 



Exit of sporoplasm. — l^ever observed, prolonged immersion in water 

 produ''ing only a gaping of the valves, with or without a falling out of 

 the capsules. 



Habitat, etc. — (xall-bladder (free-floating in and escaping with the bile) 

 of Bufo agua (toad) in every one of 50 half grown to grown individuals 

 taken at the most various times at one locality in Brazil; parasites 

 mostly multiple, sometimes as many as 50; also in young specimens 

 of Cystignafhus ocellatus (toad) from 2 localities in Brazil. On the 

 contrary they were absent from 2 large individuals of Jhifo agua from 

 other provinces of Brazil. They were also absent from all the tadpoles 

 examined and from metamorphosed toads from several localities. 



Effects. — The myxosporidia observed appeared in nowise to impair 

 the histological integrity of the gall-bladder. 



98. Cystodiscus ? ? diploxys Gurley, 1893. PI. 42, figs. 11-13. 



Gyst. — Spherical, 12 to 15 (in 1 individual 1) in number, 230 to 400 yt/. 

 Membiane rather thick. Contents rounded masses composed of fine 

 brownish granulations suspended in a viscid homogeneous liquid. In 1 

 cyst (pi. 42, fig. 12) the parasites were mixed with numerous fat like 

 globules, insoluble in caustic soda; coloring wine red with iodine. 



Spore. — Greatly resembling the "psorosperms" of fishes; elliptic or 

 slightly flattened, traversed by a ridge apparently marking the line of 

 valve junction. Sometimes showing 2 small brilliant twin grains placed 

 at one of their extremities, sometimes 4 grains disi)()sed in jiairs at the 

 2 "ends"; not visibly alfected by concentrated alkalies or feeble acids; 

 becoming brilliant and homogeneous in salt water. 



Ilahitat. — In the free state or inclosed in great spherical cysts in 

 the abdominal cavity of the butterfly of Tortrix viridana (an iu.sect). 



