68 



HENRY LESLIE OSBORN. 



side from the four blunt anterior papillae, and they are extended 

 transversely to the animal. In form they are tapering and 

 pointed, and slightly curved backward, in the form of a horn, 

 extending considerably beyond the contour of the side of the 

 animal. The oral sucker itself has a diameter of 0.4 mm. The 

 ventral sucker, while large, is smaller than the oral sucker, its 

 diameter being 0.3 mm. Its position in Fig. I is strikingly far 

 forward ; in Fig. 7 it is more nearly in the center of the body. 

 This difference is due to contraction of the neck in Fig. I, shown 

 also by the winding course of the oesophagus of that specimen. 

 The genital pore is located in front of and near to the ventral 

 sucker, in the middle line. Eyes are present in younger speci- 

 mens, but older ones do not possess them, though in these it is 



- mu dv 

 par 



mu czr 

 mu Ion 



oj mm 



FIG. 5. Transverse section in level of the posterior spermary. Cam. luc. X II 5- 

 vt., vitellaria ; mu.d.v., dorsiventral muscle; mti.cir., circular muscle of the body 

 wall ; mu.loH., longitudinal muscle of the body wall. 



possible to find scattered grains of pigment in the region of 

 the pharynx, indicating their late disappearance. Looss repre- 

 sents eyes in both the specimens figured by him, so that if they 

 are not exceptional cases, the eyes persist to a much later time 

 in the life history of B. nodulosa than of B. cornuta. 



The body wall presents the usual cuticle, destitute of spines. 

 The usual muscle layers are present, .the fibers of the outer circu- 

 lar layer are very fine indeed ; those of the longitudinal and oblique 

 layers are exceptionally large. Parenchymatous muscle is some- 

 what specially collected in each side of the body running dorso- 



