V. 



THE MYXOSPORIDIA OF THE BEAUFORT REGION. 225 



types of trophozoites described under sphairophora. The sporulating trophozoites, however, can be 

 easily distinguished on accoimt of the very different appearance of the spores and their different arrange- 

 ment within the trophozoite (fig. 24). The spores of this species are situated, as is usually the case in 

 Ceralomyxa, with the greater part of the spore parallel to the long axis of the trophozoite, only a part 

 of one valve being bent back along the rest of the spore. 



The sporulating trophozoites are somewhat smaller than in C. sphairophora, the average length being 

 about 80M, average width about 25^. 



Disporous. 



Spore. — Very characteristic. Valves greatly elongated; sporocyst very thin, the membrance on 

 opposite sides of each valve being in contact for about two-thirds of its length, forming a thin, ribbonlike 

 structure; basal third of each valve only slightly compressed parallel to the longitudinal plane (fig. 

 25, 26); terminal ribbonlike portion of each valve usually twisted so that plane of ribbon is at right 

 angles to longitudinal plane. Capsules small, prj'iforra to spherical, convergent, opening on capsular 

 margin. Coiled filaments indistinct. Sporocyst slightly constricted along sutural line. Sutural 

 plane perpendicular to longitudinal axis. Sporoplasm finely granular, filling the basal third of each 

 valve, usually extending an equal distance into each (fig. 25), but sometimes extending farther into 

 one valve than the other (fig. 26). 



Length of spore about 140-150/*; length of central portion about 45M, width about 6m; diameter of 

 capsules 3^. 



Habitat. — Found in the gall bladder of Scoliodon terrce-novce along with C. sphairophora. 



Remarks. — Although the vegetative trophozoites are indistinguishable from C. sphairophora, the 

 spores are so different that there seems to be no doubt that it should be regarded as a distinct species. 

 No spores have been observed which could be considered as in any way intermediate between the two. 



Ceratomyxa attenuata, n. sp. (PI. xvm, fig. 27, 28.) 



Trophozoite. — Vegetative trophozoites elongate, pyriform, with long, tapering posterior process; 

 at anterior end numerous long, filiform pseudopodia. Progressive movements rapid. Ectoplasm dis- 

 tinct only at anterior end. Endoplasm filled with small, refractive, yellow or brownish granules, which 

 are uniformly distributed throughout the trophozoite (fig. 27); these granules are always some distance 

 apart and are probably inclosed in very transparent spherules, which can only be distinguished w ith great 

 difficulty. While no spherules can be made out in many instances, the fact that the granules are always 

 situated at approximately equal distances from each other indicate that they must be inclosed in some- 

 thing of the kind. Between the brownish granules the endoplasm is clear and colorless, not granular, 

 except at extreme anterior end where it contains a clump of small fat globules. In small trophozoites 

 granules are much less abundant and in very small individuals entirely absent. 



During development the spores are arranged side by side with their long axes parallel to the long 

 axis of the trophozoite, the valves being bent on themselves near the middle so that the attenuated ends 

 lie along the larger basal portion. 



Length of full-grown trophozoites about 100-120^, width about 27/1. The total length varies greatly, 

 depending on the elongation of the posterior process, which in extreme cases may be drawn out to great 

 length. 



Disporous. 



Spore. — Valves greatly elongated; tmsymmetrical , one valve being about 15/j shorter than the other 

 and ending abruptly; the longer valve tapering gradually to a point (fig. 28). About midway between 

 the ends of each valve (i. e., where they were bent diu-ing development) is a thin septum, on the inner 

 side of which the remains of the parietal cell nucleus can sometimes be distinguished; external to the 

 septum the valves are empty, and in the more attenuated valve the walls collapse so that they are in 

 contact along the longitudinal plane. Capsules large and conspicuous, opening on the capsular margin. 

 Coiled filaments distinct. Sutural plane oblique to longitudinal axis; sutural line forming a distinct, 

 sinuous ridge around spore. Sporoplasm distinct, asymmetrically situated in central part of sporocyst. 



Length of spore about 115/1, width g/x; diameter of capsules 4. 5m; length of filament 6om. 



Habitat. — Both vegetative and sporulating trophozoites abundant in the gall bladder of a sharp- 

 nosed shark, Scoliodon terr<e-nov<E, taken July 8, 1915- 



Ceratomyxa recurvata, n. sp. (PI. xvin, fig. 29-33.) 



Trophozoite. — Vegetative trophozoites colorless, pyriform, with long, slender posterior process. 

 Actively motile, forming numerous filiform pseudopodia of ectoplasm at anterior end. Endoplasm 



