TPIE MYXOSPOKIDIA, OR PSOROSPERMS OF FISHES. 259 



FiDally Tlielolian's observations ou Ceratomyxa spluer alona (pp. 7(!, 

 277) indicate that perhaps a proper pigment (and not merely an extra- 

 neous one, as hteniatoidin) may exist in this genns. 



VI. CIILOROMYXUM Miugazzini, 18C0. 



Etymology not given. 



Boll. Soc. Nat. Napoli, iv, p. 160; ib., Thelohan, 1892, Bull. Soc. pliilomat. 

 Paris, IV, pp. 173, 176; ib., Gurley, 1893, Bull. U. S. Fish Com. for 1891, 

 XI, pp. 411, 412, 418; ih., Braun, 1893, Ceutralbl. f. Bakt. u. Parasitenkde, 

 XIV, p. 739; ib., Braun, 1894. Ceutralbl. f. Bakt. u. Parasitenkde, xv, p. 87. 



Definition. — Chloromyxidw with subspherical or ovate spores, whose 

 breadth does not much exceed the length; valves hemispherical; spo- 

 roplasm bilaterally and synnnetrically situated; type 6'. Icydiyii. 



Synonymy. — By reference to table on page 1 15, it will be seen that 

 Sphcerospora and My.vosoma differ in none of the characters there given, 

 the genera at present resting solely upon spore-forin. This is entirely 

 insufficient to warrant the retention of both genera, especially as any 

 reason which would justify the generic separation of the ovate from 

 the subspherical bicapsulate spores, would equally justify a similar 

 separation of the ovate from the subspherical quadrlcapsulate spores. 



From Ghloromyxum the Sphcerospora-31y,vosoma section has indeed 

 the additional character of 2 capsules as opposed to 4 in Ghloromyxum 

 proper. I have already given (p. 115) my reasons for regarding the 

 number of the capsules as a character secondary in importance to their 

 grouping and position. Sphwrospora (including il/7/x'osoma) is therefore 

 here accorded subgeneric rank. 



Ghloromyxum, sens, strict. 



Definition. — QuadricaT>sulate Ohioromyxa; type C. leydigii. 

 93. Cliloromyxum incisum Gurloy, 1893.' PI. 37, fig. 1. 



(Psorosperms of Raja batis, Leydig, Miiller's Archiv., 18.51, pp. 225-6, 234, pi. 



8, fig. 4a-/.) 

 Ghloromyxum incisum, V^nW. U. S. Fisli Com. for 1891, xi, p. 419; ib., Braun, 

 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. 



Cyst unknown. 



Myxosporidium. — Biliary-yellow, mostly roundish or somewhat elon- 

 gate, 29 to 88 /A {•01'S5--04:05"') in diameter, without or with Ito 4 pan- 

 sporoblasts (Tochterblase), most of which last contain spores. As in 

 the spore of Squatina aquatina [M. /cyrZir/ii), thesporoblasts increase at 

 tiie expense of the other portions of the cell contents until they nearly 

 till the cell (fig. le,/). 



Spore. — Sharply cuneate-ovate, ^ost^erior border radiate-incised (caus- 

 ing it to resemble a radiate-ribbed Lamellibranch shell); capsules 4, 

 situate anteriorly, converging. 



Habitat. — Free in gallbladder of Raja batis L. (skate); present in 

 great numbers. 



' Concerning the relation between this species and the next, see the latter, under 

 Synontfmy. 



