THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 107 
Liver (exclusive of gall bladder and ducts). But two species are 
known here, and these are the two which have the widest organal 
range, viz: Myxobolus ellipsoides and Myxobolus sp. 51. 
Kidney.—In only a few instances has any distinction been made 
between the stroma of the kidney and the tubules. It seems, however, 
not improbable that, as regards organal distribution, a distinction 
should be made, and the tubules be regarded as a part of the hollow 
fluid-filled urinary tract, the stroma forming a solid connective tissue 
seat. The following occur here: 
“Kidney”: MM. piriformis, M. brachycystis, M. milleri, Myxobolus sp. 
51, M. ? sp. 65, M. diplurus. 
Renal tubules: Myxobolus brevis, M. medius, Chloromyxum (S.) elegans, 
C. (S.) ohlmachert. 
Spleen.—This organ has furnished: Myxobolus piriformis, M. brachy- 
cystis, M. Ellipsoides, M. sp. 51. 
Ovary.—From this are known: Myxobolus miilleri, M. sp. 51, M. 
brevis (2 hosts), M. medius (2 hosts), M. ef. creplini, Chloromyxum (S.) 
elegans (2 hosts), C. sp. 91. 
Excretory tract.—For purposes of organal distribution, the gall and 
urinary bladders should be considered together, as they present prac- 
tically identical environmental conditions, both being internal (which 
means a uniform temperature) and both being fluid-filled. To these 
cavities may perhaps be added, as exhibiting similar conditions, the 
bile-ducts and the renal tubules. 
If, now, we consider this tract as a whole, we find that its rich and 
peculiar fauna stands in strong contrast to the species inhabiting the 
remaining organs. For we find absolutely confined to it the following: 
The Chloromyxide except only Chloromyxum dujardini, the Cystodiscide, 
except the insecticolous Cystodiscus ?? diploxys, and the Mywxidiide. 
Besides these, only the following species occur in this tract: 
(a) Inthe gall bladder: Genus incert. sp. 9, “Myxosporidium” congri,} 
Myxobolus? merlucii. 
(6) In the renal tubules: Myxobolus brevis, Myxobolus medius. 
In the following table all the species—47 in number—whose generic 
references are fairly certain and whose seats are known, are compared 
as regards their organal distribution. The unit adopted is the oceur- 
rence of 1 myxosporidian species in 1 organ of 1 host. The number of 
such “ occurrences ” is shown for each species by the Roman, and for 
each genus by the Arabic numerals. 
1Spore unknown (genus? See pp. 110,182). 
?Generic reference, in the almost entire absence of a description, by no means 
certain. 
