522 T. H. JOHNSTON AND M. J. BANCROFT. 
diameter; they were not at all abundant—five being the 
greatest number found on any single gill arch. Sections. 
revealed the structure usually present in a myxosporidian 
cyst. 
The spore is egg-shaped, the anterior end being pointed. 
There are two polar capsules situated anteriorly. The 
protoplasmic body contains a single nucleus. The inner 
margin of the envelope is indented posteriorly. The aver- 
age dimensions are:—Length of spore 11—13/; breadth 6 
— 8v; thickness 5p; length of polar capsule 5-6; breadth 
of capsule 24. An iodinophilous vacuole has not been 
demonstrated, the lack of this characteristic placing the 
Species in the genus Myxosoma. It closely resembles 
Myxosoma dujardini, a European species, from the gills of 
Scardinius erythrophthalmus and Leuciscus rutilus, both 
in shape and size, but is distinguished from it by the pres- 
ence of the indentations referred to. 
We have named the species as a recognition of Mr. D.. 
Ogilby’s assistance. 
Family MYXOBOLIDAL. 
MYXOBOLUS PLECTROPLITES 0. Sp. 
Host:—Golden perch or yellow belly, Plectroplites. 
ambiguus Richardson. 
Spores were first noticed ina stained smear from the 
kidney. Oysts were not observed with the naked eye in 
this or in any other of the nine specimens of perch examined,,. 
but in two other cases, however, on careful microscopic 
examination a few spores were found. On sectioning a 
piece of kidney known to be infected, a few small cysts. 
about 60 indiameter were discovered. In two specimens. 
of perch, Myxobolus, spores were detected in the gall 
bladder; these proving to be extremely like those from the 
kidney. It was only on prolonged examination that the 
