THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. TH 
2. Position and grouping of the capsules—Coimpared to these all- 
important characters, the mere number of the capsules is of minor impor- 
tance. For, not only does the same genus frequently show 1 or 2, 2 or 
4, but the number may even vary in the same species, as (apart from 
the entirely anomalous case of Myobolus ellipsoides, where ‘ accessory” 
capsules may develop) Myxidium lieberkiihnit shows sometimes 2 and 
sometimes 4 capsules.'. But what is never varied in the same genus 
is the topographic relation of the capsules. Thus in Myxobolus, while 
in number they may be either 2 or 1, they are never arranged otherwise 
than in one group, or placed otherwise than at the anterior end, and 
similarly in all the other genera. In Myxidiwm the capsules are 2 
or 4, but whether 2 or 4, they are always in two groups at the right 
and left extremities of the spore. Also in Oystodiscus they are 2 or 4, 
but always in two groups, which, however, are probably anterior and 
posterior in position (see p. 278). 
In the following table I have plotted out the principal characters and 
indicated their relations to generic lines. 
Comparison of generic characters in the Phanocystes. 
[Xx —present; 0—absent; ()— less usual; ——condition not known. ] 
Sym: Capsules Shell 
metry, ser ; : 
4 Inclination of 
; = plane of june- 
ellis = In two groups. tion of valves 
On ree <3 to longitudinal 
BR 8 foW) plane. 
~ i Bw : —_— 
Sales Be | At th 
fH) |= ° op kh | e , ; y 
é a 3 ov | (anterior | (aa 2 s 
Lon tol o=_ 
$ 3 E BG nee | andleft) | 0°. 90°. B | a 
q/4/ 4 |4 MGS ore ee Pla 
Myzxobolus Bitschli sens. 
BHIBCE Soe one es esisiios seeiee OSHS WER awe sel oe sesso ee x Sw Ree cee <—HA0 
Henneguya Thélohan ..} 0 | x 2 <1 |baoeBeasoslbonerososS xX Xi eee se Sess 
Chloromyxum Mingazzini-.| 0 | X 4 gn CESAE SOA a Seeteeee x — x? 0 | 0 
Myxosoma Thélohan...} 0 | x 2 df, See yee alitas a So aapete (*) = OninO 
Spherospora Thélohan.| 0 | x 2 XY Bes SARE Sule Se sekises x = Sit 0} 0 
Ceratomyxa Thélohan ..--- OF iat 2 SPN is Hosea Basse cies XE aaecccer x 0 | 0 
Oystodiscus Lutz .-.----.--- all) Slee (O14) ieee: ds CNN Etta ae SA | es ee yer >< — | 1 
Spheromyxa Thélohan.....|....|..-. OB Weeenos (Oo eeonoeraae 3Gi[ he rate gate i rates Oe eects 
Myzxidiwm Biitschli.--...-. OP seal i(oma) ene ll eetettnte eae x Orr |L Soe e. 0] 0 
| 
* From analogy and general similarity of appearance, this genus can hardly be other than bivalve, 
tC. (S.) ohlmacheri. 
tImperfect. Shell and capsules symmetrical; sporoplasm unilateral. 
From this table we may conclude that— 
1. Henneguya agrees with Myxobolus in every respect but one, the 
presence of a tail. (See also p. 206.) 
2. Thélohan’s groups, “ Myxidiées” and “ Chloromyxées,” must undergo 
rearrangement (see table below); for clearly Chloromyxum, Myxosoma, 
and Spherospora torm a compact group, with which Myxidium has no 
character of Consequence in common except the absence of a vacuole. 
1 Balbiani, 1883, Journ. de Microgr., vu, p. 274, tig. 64g. 
