ART. 12 A NEW LIVER FLUKE FROM A MONKEY SANDGROUND 3 



The body is thin and flat with weakly developed musculature. The 

 specimen least contracted, and hence chosen to represent the type, is 

 spindle-shaped, the body tapering gradually to a rounded extremity 

 anteriorly. In other specimens the preacetabular region is drawn out 

 into a rather narrow neck. The superficial cuticle is devoid of scales, 

 but the presence of numerous subcuticular cells gives it a granular 

 appearance which to some extent masks the internal structure so that 

 the more delicate details are difficult to determine. Oral sucker 

 circular in outline, from 0.22 mm. to 0.28 mm. in diameter. It is 

 terminal and ventral, with strong muscular rim nearly 90m wide. 

 The oral aperture is subterminal and semilunar in shape. Muscular 

 pharynx, 0.08 to 0.12 mm. in length, followed by a narrow esophageal 

 region, about 0.15 mm. long, which bifurcates to form the intestinal 

 ceca. Intestinal ceca simple, thin-walled, and so narrow that in some 

 specimens their presence is determined with difficulty. In other 

 specimens the ceca are about 0.12 mm. wide and run a slightly 

 undulating course posteriorly on either side of the acetabulum to 

 terminate in a small vesicle, just behind the middle of the body. 

 The course of the intestinal ceca is usually entirely external to the 

 vitellarian fields, but in some specimens the crest of the undulations 

 overlie the vitelUne glands. The acetabulum is muscular. In diam- 

 eter it ranges from 0.20 to 0.28 mm., being slightly smaller in size than 

 the oral sucker. The excretory vessel is a simple narrow tube, the 

 lateral horns of which are not visible in mounted specimens. It 

 opens at the posterior extremity of the body into a slight indentation 

 of the contour of the body. 



Male genitalia. — The testes are situated in the second quarter of 

 the body. In the convenient terminology used by Stiles and Gold- 

 berger (1910) to describe the topography of the organs of trematodes, 

 both the zones and fields of the two testes would be said to overlap, 

 and the testes abut on their internal borders. In the type specimen 

 the testes are deeply lobed and the area of the anterior testis is per- 

 haps a Uttle smaller than that of the posterior. In other specimens 

 a lobed condition of the testes is not noted. The vasa-efferentia and 

 the vas deferens are presumably too deUcate to be observed in toto- 

 mounts, but a well-developed, although small cirrus, which is some- 

 what coiled, can be seen. The genital atrium, which receives the 

 cirrus, is situated just posterior to the point of bifurcation of the 

 esophagus. 



Female genitalia. — The ovary, measuring about 0.22 mm. by 

 0.28 mm., occupies a position immediately behind the right testis. 

 It is usually ovoid in shape, sometimes almost spherical. A large 

 receptaculum seminis, about 0.13 mm. in diameter, lies posterior to 

 and in the same longitudinal field as the ovary. Neither Mehlis's 

 gland nor Laurer's canal was observed. The coils of the massive 



