AET. 17 PARASITES OF AMPHIBIA AND EEPTILIA HARWOOD 13 



measurements are equal to the smaller dimensions given are barely- 

 mature and have only a few eggs in the uterus. The body when 

 relaxed is proportionately wider than is the case with other species 

 of Brachycoeliuni. Usually it is about twice as long as wide. The 

 cuticula is thin and set with small spines in the cephalic region. 

 These disappear about the level of the genital glands. The oral 

 sucker is subterminal and nearly circular in outline. Its diameter 

 varies from 0.13 to 0.23 mm. It is about twice the size of the 

 acetabulum. In the type specimen the oral sucker is 0.23 mm and 

 the acetabulum 0.125 mm in diameter. This in my experience rep- 

 resents the extreme variation from the mean of 2:1. The acetab- 

 ulum has its cephalic margin 0.32 to 0.42 mm from the anterior 

 end and, therefore, is wholly behind the caudal limits of the cephalic 

 third of the body. The prepharynx is lacking, and the oval pharynx 

 measures 42^ to 50/a by 60/x to 65/la, with the long diameter lying 

 transversely. The esophagus is short, being about 30)U, long. From 

 its caudal extremity the intestinal ceca extend almost directly lat- 

 erad. They are largely obscured by the vitellaria. The ovary is- 

 lateral, but it may lie on either side. It is usually nearly circular in 

 outline and very variable in size, being relatively larger in younger 

 specimens. It averages 100/a in diameter. The ootype and Mehlis's- 

 gland can not be seen in whole mounts, but in sections they plainly 

 show on the latero-dorsal side of the ovary. The seminal receptacle 

 could not be located. The uterus fills the body behind the ovary, 

 partially if not wholly obscuring the testes and Mehlis's gland. The 

 eggs are 29/a to 31/i by 40/x, to 42;u,. The vitellaria are well developed. 

 They fill the lateral fields from the ovary to the oral sucker, and a 

 band of follicles extends across the body between the oral sucker 

 and the genital pore. As the digestive system is included in this 

 region these follicles make observations on this system difficult in 

 whole mounts. In the median field, they are confined to the dorsal 

 half of the body, but laterad they lie both dorsal and ventral to all 

 other organs. The testes are level with the acetabulum and posterior 

 to the ovary. The testis on the ovarian side is closely pressed against 

 the ovary but is, nevertheless, slightly caudal to its mate. The vasa 

 efferentia could not be traced. The genital pore lies at the cephalic 

 margin of the acetabulum. The cirrus sac, containing a seminal vesi- 

 cle, runs first cephalad and then curves laterad away from the 

 ovary, and its distal end lies at the level of the genital pore. The 

 excretory vesicle is quite concealed by the uterus in whole mounts, but 

 in sections it shows as a characteristic simple sac extending to the 

 caudal limits of the testes. 



