LECUDINA. 83 



Genus LECUDINA Mingazzini, 1891. 



Gregarina (part), Kolliker, 1848, p. 35. 

 Lecudina, Mingazzini, 1891, p. 469. 

 Doliocystis, Leger, 1893, pp. 204-6. 

 Lecudina -\-Ophiodina, Mingazzini, 1893, p. 51. 

 Ophioidina, Minehin, 1903, p. 196. 

 Doliocystis, MLnchin, 1903, pp. 202-3. 



Lecudina, Kamm, 1922, pp. 10, 23-6 ; Reichenow, 1929, p. 892 ; 

 1932, pp. 31-2; 1935, p. 368. 



Body cylindrical or ovoid, cytoplasm of the anterior portion 

 distinctly marked ofiF by the possession of fine granules. Epi- 

 merite caducous or invaginable, able to take for any single 

 species only a variety of well-determined forms. Intestinal 

 parasites of Polychaetes. 



23. Lecudina brasili Ganapathy & Aiyar. (Fig. 25.) 

 •f Lecudina sp., Ganapathy & Aiyar, 1937, p. 292. 



Youngest stages intracellular within the gut-epithelium, 

 ovoid in outline, with a sKght concavity at one end. The full- 

 grown trophozoite is widest at about a third of its length 

 from the anterior end, and the nucleus, which is spherical, 

 is situated at that level. The pellicle is uniformly thick and 

 the cytoplasm granular, except in the prolongation at the 

 anterior end. These trophozoites lie in the lumen of the gut, 

 attached to the epithelial cells by an epimerite. In the 

 fuUy evaginated condition the epimerite has a truncated base, 

 with a slender prolongation ending ia a darkly staining anchor- 

 plate. The peUicle does not appear to be continued over the 

 epimerite, which has therefore been interpreted as endoplasmic 

 in origin and is capable of retraction and evagination. 

 The epimerite is entirely extracellular. In the retracted 

 state the anterior region of the organism presents a slight 

 concavity. When the organism detaches itself the anchor-plate 

 is left behind, and a bubble of cytoplasm appears to protrude 

 from the anterior end ; this is in reahty the evaginated epi- 

 merite after it has become detached from the gut-epithehum. 

 In sections the whole epimerite, excluding the anchor-plate, 

 shows faint longitudinal striations. Association takes place 

 between two mature trophozoites, which become surrounded 

 by a spherical gametocyst. Two kinds of gametes are produced 

 and conjugation is anisogamous. Sporocysts are oval in 

 outline, with a characteristic thickening at one pole. Eight 

 sporozoites are developed inside each spore. 



Dimensions. — Trophozoites measure ISO/x by SOfM, length 

 of epimerite 10-12 /x ; gametocysts measure 75 ju, in diameter ; 

 sporocysts measure 6 Ju, by 4 |u.. 



Remarks. — Ganapathy and Aiyar (1937) have recently 

 communicated a paper describing the different stages in the 



g2 



