THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 135 



DESCRIPTION OF GENERA AND SPECIES. 



Tabular Key. 



The following tabular key includes all the species, which can by any 

 reasonable possibility be construed as myxosporidian, with their prin- 

 cipal characters plotted out. The order of arrangement is a trifle more 

 artificial than that found in the text. 



Descriptions of the following species are omitted, as I believe there 

 is no rational chance of their being Myxosporidia : 



Psorospermium ha'clcelii Hilgeudorff, 1883. 



(Parasite oi Astacus fluviatUis, Hiickel, 1855, De telis quibnsdam Astaci fluvi- 

 aiilis, luaug. Dissert. Friedr. Willielni. Univ. Berlin, p. 42, pi. 2, fig. 25A-C; 

 ib. Hiickel, 1857, Ueber d. Gewebe d. Flusskrebses, Miiller's ArcLiv., pp. 561-2, 

 pi. 19, fig. 25A-C; ib., Grobben, 1878, Beitriige z. Keuntn. d. miinnl. Gesch- 

 lechtsorg. d. Dekapoden ; not seen. 



Psorospermium hwckeUi, Bericht d. Gesellscli. Natnrf. Freunde Berlin, pp. 179- 

 181 (not seen) ; ih., Zacharias, 1888, Ueber Psorospermium hackelii, Zoolog. 

 Anzeiger, XI, pp. 49-51 (abstr. Journ. Roy. Micr. Soc. Loudon, 1888, viii, p. 

 240); (6., Wierzejski, Kleine Beitriige z. Kenutn. d. Psoros2)ermium hackelii, 

 Zoolog. Anzeiger, xi, pp. 230-231 (abstr. Jour. Roy. Micr. Soc. Loudon, 



1888, VIII, p. 598). 



This form and the next have never been definitely referred to the 

 Myxosporidia., but Prof. Linton's bibliography of the '■'■ Fsorospermuv^'' ^ 

 includes the articles containing them. They have no connection with 

 the Myxosporidia. 



Psorospermium Zz/fcrHaria; Vallentin, 1888. 



Zoolog. Anzeiger, xi, pp. 622-623; abstr. Jonrn. Roy. Micr. Soc. London, 



1889, pp. 75-76. 



See note on preceding. 



Pfeifier^ states that Myxosporidia were found by Leuckart and 

 Lieberkiihn in the gall bladder and the kidneys of toads. JS^ow, the 

 assertion, in so far as it concerns Leuckart, is, I suspect, an error. It 

 was probably copied from Lutz,-' who says : 



The Mi/rosporidia are, as it is known, entirely parasitic, and in the large major- 

 ity of (;ases live upon fishes. The only one of the authors accessible to nu' who men- 

 tions their occurrence in tlie Amphibia is Leuckart, who found them l're(]uently in 

 the urinary bladder of frogs, and also mentions the occurrence of a species descrilied 

 by Lieberkiihn in the kidney. 



I have been unable to find any such observation of Leuckart's, and 

 correspondence with both him and Dr. Lutz failed to elicit a refer(MU!e 

 or a substantiation of the statement; so that " Leuckart" is here prob- 

 ably an error for Lieberkuhn. Furthermore, there is absolutely noth- 

 ing to indicate the myxosporidian nature of the forms described by 



' Bull. U. S. Fish^Com. for 1889, ix, p. 102. 



^Virchow. Archiv. f. pathol. Auat. u. Physiol., iierliu, cxxii, p. 557; Dio Protozopn 

 als Krankheitserreger, 1891, 2 ed., p. 134; receutlv copied by ( >hliiKicli<T, Journ. 

 Amer. Med. Assoc, 1893, xx, ]>. .5()2. 



»CentralbI. f. Bakt. u. Parusiteukde, 1889, v, p. 84. 



