290 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Spore. — Possessing only one plane of symmetry, viz, the valve- 

 junction plane, difl'ering in this respect from most other myxosporidian 

 spores, Avhich have another such plane perpendicular to valve-junction 

 plane. Form very remarkable, comparable to a i)od whose acuminate 

 extremities are oppositely directed; length ( ?), 4 to 5/i ; breadth (?), 8 to 

 9/t . Capsules, 1 at each end (or wing?), their long axes oblique and 

 oppositely directed with reference to the long (transverse?) diameter of 

 the spore. Filament extrusion very difficult of production; produced 

 by nitric acid; length of filament, 12/<; sporoplasm nonvacuolate. 



Hahitat. — Gall bladders of Ojius tricirratus {=Motella tricirrata), 

 Syngnathus {=Enteluriis) ceqiioreus (pipefish), and Blennius pholis, all 

 from Eoscofl'; in B. phoUs from Concarneau; in Siphostoma {= Syngna- 

 thus) acns (pipefish) and Callionymus lyra. 



The description of this species is not sufficient, in the absence of 

 figures, to warrant a positive opinion as to its generic affinities. I have 

 attempted to construct from Thelohan's description a diagram of the 

 spore, but without success. The prevalent very loose use of such terms 

 as "ends," "extremities," "length," "breadth," etc., renders them 

 invalid for taxonomy, and the only course open seems to be to retain 

 this provisionally in Myxidium, noting that in its bivalve structure it 

 differs markedly from M. Ueherl-Uhnii, the type species. 



102. Myxidium? sp. iiicert. PL 47, fig. 6. 



Psorosperms of Baja hatis, Leydig, 1851, Miiller's Arcliiv., pp. 226, 234, pi. 8, fig. 

 4^; ib., Leuckart, 1852, Archiv. f. physiolog. Heilkde., xi, p. 436, fig. 216. 

 Myxidium? sp. Guiiey, 1893, Bull. U. S. Fish Com. for 1891, xi, p. 420. 

 No description. The distinctness of this form from Chloromyxum 

 incisum was recognized by Leydig (p. 234). 

 Habitat. — Free in bile ducts of Ra^a hatis L. (skate). 



