211 



Spore. — Of the form aud size of Chloromi/.vum dujardlni. Capsule only 

 1, situated on one side of the anterior end, obliquely directed. 



Habitat. — On Lnheo niloticuN from the Nile. 

 35. Myxobolus piriformis Thdlohiin, 1892. Plato 13, lig. 3 (pars), J (2)ars) ' ; j)!. 18. 

 (Prforospcrras of the teucli (jtars) Balbiani, 1883, Jouru. de Microgr., vii, pp. 

 197-198, fig. m h, c, ? d-f; ih. {pars) Balbiani, 1884, Lc(;ons sur les Sporo- 

 zoaires, pp. 12.3-6, fig. ill), c, ? d-f; pi. 4, figs. 1, 2, 3A {jmrs)^ ? 3B,C; 

 ? ib. (j)ars) Pfeifter, 1890, Die Protozocu als Kranlieitserregcr, 1 ed., pp. 

 48,55, fig. 16; ? ib. {par.s) 1891, 2 ed., p. 132, fig. 56. 

 Myxobolus piriformis, Bull. Soc. philomat. Paris, iv, p. 177; ib., Gurley, 1893, 

 Bull. U. S. Fish Com. for 1891, xi, p. 414; ib., Braun, 1893, Centralhl. f. 

 Bakt. u. Parasitenkde, xiv, p. 739; ib., Braun, 1894, Ccntralbl. f. Bakt. u. 

 Parasitenkde, "xv, j). 86. 

 Synonymy. — M. Thelohan informs me (letter, 1803) that : 

 M. piriformis has very i)robably been seeu by Remak, although his figures aud his 

 descriptions do not prove it absolutely (pi. 5, fig. 5). He does not figure the polar 

 capsules, but his figures almost certainly belong to the species in question. 



Fig. 8 represents 2 spores from the kidney- of the tench, which I do not know to 

 what species to approximate. The presence of 2 capsules separates them from M. 

 piriformis. The form of its spores and the small size of the capsules do not x^ermit 

 of its approximation to any of the forms that I have encountered. 



The typical spore of M. jnriformis contains but 1 polar capsule. As in all species, 

 one can find monstrous spores which inclose 2 capsules, but they have seemed to me 

 very rare. This species is often accompanied, above all in the spleen of the tench, 

 by IT. ellipsoides. Almost all the spores with 2 capsules, represented by the authors, 

 belong, I believe, to the spores, more or less monstrous, of this last species. 



Balbiani considered 21. piriformis a degraded form of 21. ellipsoides. I have been 

 able to convince myself that this mode of view is not correct. It is a species abso- 

 lutely distinct and well characterized, as I have been able to determine by numerous 

 observations. 



After reading the above, I lestudied the synonymy as between this 

 species and ^^. hrachycystis, and can not but feel tluit all of Kenuik's 

 figures are referable to 1 species, which probably is, as Thelohan thinks 

 aud contrary to my former opinion,' distinct from his M. inriforniis. 

 The following are the conclusions at which I have arrived: 



(fl) Remak's figures are referable to 1 species. His fig. 8 (referred to 

 in the second paragraph of the above quotation) is not from the kidney 

 but from the spleen. There appears to me to be, especially in view of 

 Eemak's statements which tend to show that he considered the question 

 carefully, no ground for a separation between these 2 developed spores 



' The figures in the rows on Balbiani's plate iv, fig. 3, arc numbered in order from 

 left to right, in the reproduction of it on pi. 13, fig. 3. The proper specific refer- 

 ences of some of the figures of groups 3 aud 4, on that plate, are dubious. The fol- 

 lowing is about all that can be safely said at i)reseut : 



Indeterminate: Figs. 3 B, C; Ul-f. (either M. piriformis or M. ellipsoides). 



Myxobolus piriformis : Figs. 3 A, Nos. 1, 2, 6 ; 47>, c. 



Myxobolus ellipsoides: Figs. 3 A, Nos. 3, 4. .5, 7 (the last with .some certainty, the 

 rest probalily, "alHiormal" spores) ; l((. 



^These spores (Keuuik's fig. 8) anr from the si>lfen. 



3 Bull. U. S. Fish Com. for 1891, \i. ]). lo;). sccuml footnote, wliere it is stated that 

 1 Myxobolus species possesses, pciliaps incoustautly, a single capsule. At that time I 

 inclined to fuse M. brachycyatia wilii .1/. piriformis. 



