V 



222 BULLETIN OF THE BUREAU OF FISHERIES. 



DESCRIPTION OF SPECIES TAKEN AT BEAUFORT. 



Suborder MYXOSPOREA. New suborder. 



Family CERATOMYXID^ Doflein. 



Genus Leptotheca Thelohan. 



Leptotheca fusifonnis, n. sp. (PI. xvi, fig. 1-2.) 



Trophozoite. — Vegetative trophozoites pyrifortn, tapering gradually toward the posterior end, which 

 usually terminates in a long, slender process; colorless, transparent. Progressive movements rapid. 

 Endoplasm distinctly granular, the granules being more abundant at the anterior end. 



Length of full-grown trophozoites about 50^1, width about it,ix. 



Disporous. 



Spore. — Elliptical when viewed from above (fig. i); base of valves circular in cross section but 

 distally are somewhat compressed parallel to the longitudinal plane, so that when viewed from the 

 capsular side the spore appears distinctly fusiform (fig. 2). Sutural plane slightly oblique to longi- 

 tudinal iixis; sutural line forming a distinct ridge. Capsules distinct, located at some distance from the 

 capsular side ;md opening on opposite sides of the spore. Sporoplasm finely granular; confined to the 

 central part of spore and not extending into the ends of the valves. 



length of spore i6m, width qm; diameter of capsules 4. 5m; length of filament 30/i. 



Habitat. — Both vegetative and sporulating trophozoites abundant in the bile of a hammer-head 

 shark, Cestracion zygcena, taken July 11, 1914. 



Leptotheca scissura, n. sp. (PI. xvi, fig. 3-8.) 



Trophozoite. — Young vegetative trophozoites elongate, with long attenuated posterior process; 

 usually slightly constricted just posterior to roimded anterior end, which bears numerous long, filiform 

 pscudopodia (fig. 3). Progressive movements rapid. Ectoplasm distinguishable only at anterior end, 

 where it gives rise to pseudopodia. Endoplasm usually filled, except in verj' young individuals, with 

 small, clear, colorless spherules, which are only visable under high magnification. As trophozoites 

 increase in size, spherules become larger and more prominent. Later the spherules become distinctly 

 yellow and contain one to several dark-brown granules, which increase in size and numbers and finally 

 collect in an irregular clump at the center of spherules (fig. 4-6). In some cases the spherules may 

 finally become almost entirely filled with these granules. Size of spherules in same trophozoite uniform 

 but increases as trophozoites grow older. In rare cases the brov\'n granules may be entirely absent 

 even in sporulating trophozites (fig. 7). The spherules are arranged in definite rows, embedded in a 

 clear, homogeneous matrix, giving a very characteristic appearance to the trophozoite. For a short 

 distance at the anterior end spherules are entirely absent, the endoplasm being distinctly granular and 

 containing numerous small fat globules. The larger trophozoites are usually distinctly flattened dorso- 

 ventrally. The posterior end may present a characteristic ragged or frayed appearance (fig. 4, 5), due 

 to the endoplasm being drawn out into a number of long, slender processes, which when large enough 

 contain one or more rows of spherules. Occasionally two or more adjacent processes may fuse (fig. 5), 

 so that the posterior region of the trophozoite has the appearance of a network composed of anastomosing 

 strands of protoplasm. 



Average length of full-grown trophozoite about 125-150/1, width about 20-25^. The longest tropho- 

 zoite observed was 195M long, with an extreme width of 16/1. 



Disporous. 



Spore. — Elliptical from above, somewhat flattened along postcapsular side (fig. 8). Sutural line 

 distinct; sutural plane at right angles to longitudinal axis. Capsules and capsulogenous cells distinct, 

 the capsules opening at some distance from the capsular margin. Sporoplasm distinct, finely granular, 

 nearly filling both valves. 



Length of spore 22^, width iim; diameter of capsules 4n. 



Habitat. — Abimdant in the gall bladders of Dasybatis hastatus and Pteroplatea maclura during July 

 and August. Lives floating freely in the bile or attached to wall of gall bladder. 



Remarks. — The structure of the spherules is very similar to that of C. sphcerulosa Thelohan, but 

 in other respects this species is very different. 



