226 BULLETIN OF THE BUREAU OF FISHERIES. 



filled with large, homogeneous Spherules (fig. 29, 31) which average about iom in diameter. In some 

 cases spherules are crowded so closely together as to be considerably distorted from original spherical 

 shape. Apparently the density of the spherules may vary considerably in different individuals, since 

 there is great variation in their appearance in stained material. This is especially evident in Giemsa 

 preparations, where in some individuals the spherules are well defined (fig. 30); in others they have so 

 disintegrated in drying as to be practically indistinguishable. This is particularly noticeable in indi- 

 viduals with the largest spherules. Surrounding the spherules is a colorless, distinctly granular endo- 

 plasin, the granules being especially abundant at the anterior end, where for a short distance the 

 spherules are absent. 



Total length of full-growTi trophozoites about 130-175M, length exclusive of posterior process about 

 lOOM. 



Disporous and polysporous; trophozoites containing from 2 to 10 spores observed. Usually more 

 than 2 spores formed, 6 and 8 being the most common numbers observed. It is of interest to note that 

 the number of spores formed is not always an even one, 3, 5, and 7 spores being obser\'ed in some cases, 

 indicating that the spores are developed singly from distinct sporoblasts and not necessarily in pairs. 

 Fig. 30 shows a portion of a trophozoite containing 3 distinct sporoblasts and 3 generative cells which 

 doubtless give rise to sporoblasts. Figure 31 also shows a trophozoite containing several sporoblasts, 

 although the individual sporoblasts can not be distinguished in every case. 



Spore. — Very characteristic; valves greatly curved toward the postcapsular side (fig. 32), usually 

 symmetrical, but occasionally one may be much more incurved than the other (fig. ;i^); in some cases 

 the ends may even overlap. Valves circular in cross section at the base but toward the ends greatly 

 flattened parallel to the longitudinal plane the walls of the opposite sides being in contact. Ends of 

 valves sharply pointed. Sutural line distinct. Capsules large and conspicuous, opening at some dis- 

 tance from the capsular margin. Coiled filaments distinct. Sporoplasm distinct, finely granular, 

 usually extending farther into one valve than the other. 



Length of spore between points of greatest curvature about i6m, width 8-9^1; diameter of capsules 



4-SM- 



Habitat, — Both vegetative and sporulating trophozoites abundant in the gall bladder of a hammer- 

 head shark, Cestracion zygccna, taken July n, 1914. 



Remarks. — In addition to this species the gall bladder contained large numbers of Leptotheca fusi- 

 /ormis, n. sp.; Ceratomyxa mcsospora n. sp.; and Chloromyxum leydigi Mingazzini, so that the bile was 

 fairly swarming with MjTcosporidia. 



\ Ceratomyxa lunata, n. sp. (PI. xvin, fig. 34, 35; pi. xi.x, fig. 36, 37.) 



Trophozoite. — Vegetative trophozoites pyriform, becoming rounded after being on the slide for a 

 short time. Progressive movements slow. Endoplasm filled with large, homogeneous spherules, which 

 are usually colorless, sometimes light yellow; spherules occasionally inclose several small, brownish 

 granules. At extreme anterior end the endoplasm contains numerous small fat globules. 



Disporous. 



Spore. — The spores show considerable variation in size and form. The larger and more typical are 

 more or less crescent -shaped ; symmetrical ; valves distinctly curved toward postcapsular side (fig. 34-36), 

 the cur\'ature often being more marked than in the figure ; ends of valves more or less rounded. Sutural 

 plane slightly oblique to longitudinal axis (fig. 37); satural line forming a distinct ridge. Capsules large, 

 distinct, situated a short distance from capsular margin and opening on opposite sides of spore. Coiled 

 filaments distinct. Sporoplasm distinct, finely granular, symmetrically situated, extending an equal 

 distance into each valve and filling entire space around capsules. Smaller spores (fig. 36, 37) differ from 

 larger chiefly in size; die valves are much shortened and have a greater ctu-vature toward the postcapsu- 

 lar side, while the ends are more distinctly rounded. 



Length of largest spore observed 38M, width 9/1; diameter of capsules 4m; length of filaments 37^. 

 This was an exceptionally large spore, the average length of the larger spores being about 30^1, the other 

 dimensions being same as given above. Length of smallest spore observed 15/1, width ■jii; diameter 

 capsules 3^. 



Habitat. — Large numbers of vegetative and a few sporulating trophozoites were present in the gall 

 bladder of a tiger shark, Galeocerda iigrinuj, taken August 8, 1914. 



Remarks. — The great variability in the spores was probably due to the fact that they were for the 

 most part formed under abnormal conditions after tlie trophozoites had been placed on a slide and cov- 



