. Bulletin of the British Museum (Natural History). . Fig. 19 Disloma gigas: ex Liivanis imperialis: (A) whole specimen (modified after Setti, 1894); (B) specimen from collection (modified after Blanchard, 1891b); (C) specimen from collection (modified after Monticelli, 1889); (D) transverse section at the level of the gonads (modified after Setti, 1894); (E) transverse section at the level of the last fifth of the body (modified after Setti, 1894). Scale: (A, B, C) 10 mm. [c, gut-caecum; e, excretory vesicle; ?mo, possibly Manter's organ; t, testis; u, uterus; v, vitellarium.] Altho
. Bulletin of the British Museum (Natural History). . Fig. 19 Disloma gigas: ex Liivanis imperialis: (A) whole specimen (modified after Setti, 1894); (B) specimen from collection (modified after Blanchard, 1891b); (C) specimen from collection (modified after Monticelli, 1889); (D) transverse section at the level of the gonads (modified after Setti, 1894); (E) transverse section at the level of the last fifth of the body (modified after Setti, 1894). Scale: (A, B, C) 10 mm. [c, gut-caecum; e, excretory vesicle; ?mo, possibly Manter's organ; t, testis; u, uterus; v, vitellarium.] Although fixed forms tend to exhibit transverse rugations, the body-surface can be considered smooth, as these are probably produced by contraction. The large ventral sucker is about four times as large as the oral sucker, which opens subterminally. The former possesses a marginal, fluted flange, which is apparently external in live specimens and lies within the margin of the ventral sucker in fixed material. This feature has been noticed by all of the authors who have described this species. The terminal excretory pore is also very evident superficially. The body-wall has a thick tegument beneath which lies a thick layer of circular muscle. On the inner side of this layer there are two layers of longitudinal muscle. The outer contains small muscle-bundles and the inner large bundles. These two layers tend to be somewhat interspersed, the outer longitudinal muscle-bundles lying between those of the much larger inner longitudinal muscle-bundles (Fig. 19E). There are no data concerning the prepharynx and pharynx, but there is apparently a short oesophagus which gives rise to two narrow caeca. These pass posteriorly, following a sinuous course, to end blindly close to the posterior extremity. The caeca possess, over at least some of their length, a lining of extremely long villi, which measure 250-300 x 12-14 (xm and extend deep into the lumen (Fig. 19E). In other regions (Fig. 19D) th
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