THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 135 



DESCRIPTION OF GENERA AND SPECIES. 



Tabular Key. 



The following tabnlnr key iuoludes all the species, which can by any 

 reasonable possibility be construed as myxosporidian, with their prin- 

 cipal characters x>lotted out. The order of arrangement is a trille more 

 artificial than that found in the text. 



De>;cri])tions of the following species are omitted, as I believe there 

 is no rational chance of their h&mg Myxosporidia: 



Psorospermium ha-clceUi Hilgendorff, 1883. 



(Parasite of Asfacus fluviatiJis, Hackel, 1855, De iells quihuHdam Asfaci flnvi- 

 aiilis, Iiiarig. Disstjrt. Frietlr. Williclui. Univ. Beiliu, p. 42, pi. 2, lig. 25A-C; 

 ib. Hiickel, 1857, Ueber d. Gevrebe d. Flnsskrebses, Miiller's ArcLiv., pp. 561-2, 

 pi. 19, fig. 2oA-C; ib., Grobben, 1878, Beitriige z. Keimtn. d. miinnl. Gescb- 

 lecbtsoig. d. Dekapoden ; not seen. 



Psorospermium hwckelii, Bericbt d. Gesellsch. Natnrf. Freunde Berlin, pp. 179- 

 181 (not seen) ; ib., Zacharias, 1888, Ueber Fsorospcrmium hackelii, Zoolog. 

 Anzeiger, xi, pp. 19-51 (abstr. Joiiru. Roy. Micr. Soc. London, 1888, vm, p. 

 240); i&., Wierzejslci, Kleine Beitriige z. Kenntn. d. Vsorospermium hackelii, 

 Zoolog. Anzeiger, xi, pp. 230-231 (abstr. Jonr. Roy. Micr. Soc. London, 



1888, VIII, p. 598). 



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

 Myxo.<iporidia, but Prof. Linton's bibliography of the '■'■Fsorospermim''''^ 

 includes the articles containing them. They have no connection with 

 the My.vosjioridia. 



Psorospermium luccrnariwYnllentm, 1888. 



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



1889, pp. 75-76. 



See note on preceding. 



Pfeift'er^ states tliat My.rosporidia were found by Leuckart and 

 Lieberkiihn in the gall bladder and the kidneys of toads. Now, the 

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

 was probably copied from Lutz,-' who says: 



The Myxosporidia are, as it is known, entirely parasitic, and in the largo major- 

 ity of cases live upon fishes. The only one of the authors accessible to me who men- 

 tions their occnrreuco in tlie Amphibia is Leuckart, who found them frequently in 

 the urinary bladder of frogs, ami also mentions the occurrence of a species described 

 by Lieberlciihu in the kiduey. 



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

 correspondence with both him and Dr. Lutz failed to elicit a reference 

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

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

 ing to indicate the myxosporidian nature of the forms described by 



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



'^Vlrchow. Archiv. f. pathol. Anat. u. Pliysiol., Berlin, cxxii, p. 557; Die Protozpen 

 als Krankheitserreger, 1891, 2 ed., p. 134; recently copied by Ohlmachcr, Jouru. 

 Amer. Med. Assoc, 1893, xx, p. 562. 



•■' Centralbl. f. Bakt. u. I'arasitenkde, 1889, v, p. 84. 



