2.—THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES, AND 
THE EPIDEMICS PRODUCED BY THEM, 
By RK. EK. GuRLEY, M. D., 
Assistant, U. S. Fish Commission. 
TABLE OF CONTENTS. 
Page. Page. 
GN aENeNIRILTOT a cise ca 12 (a\sen= im latoidlsi ais wisn = 65 | Description of genera and species—Cont’d. 
General description of the Myxosporidia. .. 71 OrdorGryptocystese. 3-4 -saceeteeseeeernis 190 
I. Nomenclature and definition ------ 71 Hamilys GLU Geld ee). 22.5 a saleeetas ee 190 
JUL, Likos a nel Gye s = BBS Bee Spee ooeceese 73 Genus Gluces.-2--- 4. saseeenaae te 191 
General description of structure. - 73 Genus Pleistophora................ 194 
Detailed description of individ- Genus Thelohania ..--...-.....-... 195 
TL REPU CUAEGS! qs siete sai See oe 75 | Ordo Phenocystes) > -sees2-08- 45a 205 
Le Zoolomicall position... ..-....---- 93 | amily Myxobolidie s-2-5 .ase-e so see 206 
GV oO TS DE CO UGLON ston a/=ieyetaresais ais = laiainricls 100 Gents) Myx oboluse so. eae. os eee 206 
Vie LORS IN CANON. assem <i otelelsiewle eset 112 Family Chloromyxid@ .....--.-.----- 258 
Wale a bnOlOp yee a= ae i maria re nec 117 Genus Chloromyxum .... -:.--...-. 259 
VIL. Microscopic technique ...--. seakis 119 Subgenus Spherospora .-....---- 265 
VAUOES 1th tity: hoes Abele sesecpeooSeoeeeee 120 Genus! Ceratomiyxas-< 2s -seeme nae 274 
OEE DHOPTAD IY mei a sent sciss ee tose ni 123 Family Cystodiscid@ ....-....!...-... 278 
Descriptions of genera and species......-... 135 Genus Cystodiscus......---.-.....- 279 
Tabular key to species ..--...- nee ae aoe 138 Genus Spheromyxa...--...--..5-.. 282 
Non-myxosporidian species .......--... 166 Ramily Myxidiidee:: 23532 2¢-52+-. 2a 283 
Species more or less probably myxo- Genus) Miyxidanmy se. see acini ae 283 
Re PEAG USE siete iaiaie nero Soa ae = 38 181 | Explanation of plates/...--..4---.22---.-5- 291 
PETUG OMY ZOSPOTIOUG 50 < nacne cote s-mc ee GO; Ulin (eK) te shaw a ce/aaine cetswwtes nls satel mcleeuesieiinee Ny 
INTRODUCTION. 
Up to the present time very little attention has been paid to the 
diseases of fishes, and to their parasites from the standpoint of the 
effect produced by them upon the host. Yet there can be no doubt that 
a knowledge of such diseases would be of great practical value. Any 
one who considers the proportions that fish epidemics may attain will 
hardly be inclined to question the utility of searching investigation in 
this direction. Thus. to take a single instance, in the epidemic of 1884 
in Lake Mendota, Prof. Forbes! states that: 
It was estimated that fully 300 tons had died up to that time. On August 7 the 
Madison Transcript reported that 200 tons had been hauled away by the city 
authorities during the four weeks preceding and that the fishes were still dying: 
Epidemics of similar extent have been reported in Europe. 
The important results in the way of prevention of epidemics among 
domesticated animals and cultivated plants obtained as the result of 
Scientific investigation afford some ground for the hope that similar 
1 Bull. U. S. Fish Com. for 1888 (1890), vir, p. 482. 
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