160 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



strict o) when the latter is more completely described. At the present 

 time, however, we feel justified in regarding the two forms as distinct. 

 While comparing L. oswaldoi with other closely related forms of the 

 genus Lyperosomum, it has been made clear to us that L. skrjahini 

 (Solowiow, 1911), described from the same hosts as L. longicaiida, 

 must be considered a direct synonym of the latter. Further, it is our 

 opinion that L. urocissae Yamaguti, 1939, is a synonym of L. os- 

 waldoi. 



Genus LUTZTKEMA Travassos, 1941 

 LUTZTREMA MONENTERON (Price and Mcintosh, 1935) 



Figure 34, a-d 



Lyperosomum moncnteron Price and McIntosh, Proc. Helm. Soc. Washington, 



vol. 2, pp. 63-64, fig. 12, 1935. 

 Lutztrema monenteron Travassos, Mem. Inst. Oswaldo Cruz, vol. 36, pp. 336-338, 



1941. 



The material in the present collection agrees very closely with that 

 described by Price and Mcintosh (1935). The present study has 

 brought out several features that might be of aid in recognizing the 

 species as being separate and distinct from its closest relative, L. 

 ohliquum (Travassos, 1917). These features only will be considered. 

 The body of the relaxed specimen (fig. 34, a) is widest in the region 

 of the anterior testis ; it tapers gradually from this point toward both 

 ends. Although aspinose, the cuticle usually exhibits fine transverse 

 ridges over most of the body while small, conical, retractile sensory 

 papillae appear on the surface of the oral sucker and along the margins 

 of the preacetabular region of the body ; these papillae are readily ob- 

 served on living worms. The acetabulum (fig. 34, &) is strongly mus- 

 cular and cup-shaped with a deep lumen ; it is usually set in the bottom 

 of an acetabular depression. The ratio of the width of the oral sucker 

 to acetabulum varies from 1 : 1.65 to 1 : 2. The cecum passes between 

 the testes and between the posterior testis and ovary, and without 

 exception terminates well in advance of the posterior end of the 

 body, usually terminating anywhere from just posterior to the vitel- 

 laria to a point about one-third the distance from the vitellaria to the 

 posterior end of the body. The common collecting tubules of the 

 excretory system arise from the anterior end of the excretory vesicle 

 and pass anterolaterally to a level midway between the testicular 

 zones where they divide into anterior and posterior main collecting 

 tubules. Each of the main collecting tubules gives rise to three short 

 accessory tubules, each of which branches into two capillaries. Each 

 capillary tubule terminates in a single flame cell, thus establishing a 



