TREMATODES OF THE NORTHUMBEBLAND COAST 443 



the tube being lined with fine spines with their apices directed 

 forwards. These spines are not continued into the anterior 

 part of the cirrus and are never exserted, so they probably 

 serve the purpose, as Stossich* suggests in the case of 

 Stephanochasnnis pristis Desl., of preventing the sperms from 

 going back after leaving the body. 



The ovary is situated in front of the foremost testis, and is 

 separated from it by a space of about 0"i2 mm. It corres- 

 ponds in shape and size with the larger testis. The uterus, 

 full of eggs, winds behind the ovary, and then turns and 

 twists in many loops in front, filling up the middle part of the 

 body nearly as far as the vesicula seminalis. Here it dilates 

 and runs forwards as a muscular vagina, which opens into 

 the genital pore by a thick lip. No receptaculum seminis 

 was observed. The vitellaria are not strongly developed, and 

 consist of two thin bands of small spherules running along 

 each side of the body close to the intestinal lobes, beginning 

 in front of the posterior part of the testes, and ending at about 

 the level of the central part of the vesicula seminalis. A 

 transverse duct from each side unites with its fellow in a 

 vitellarian receptacle just behind the ovary. 



The ova are numerous, measuring o*io mm. x 0*05 mm., 

 each end being rounded equally. They are coated with thick 

 yellow shells, and in the anterior half of the uterus have 

 developed into miracidia with a conspicuous eye-spot. Near 

 the genital pore the shells are empty, the miracidia having 

 perhaps escaped. Empty shells were seen in the oral sucker. 



This Trematode almost certainly belongs to the sub-family 

 Echinostomiuce Looss, although differing from all the hitherto- 

 known genera in the presence of miracidia in the eggs and in 

 the weakly developed vitellaria, which do not extend into 

 the posterior region of the body behind the testes. In these 

 respects it resembles Parorchis Nicoll,f and in the presence of 

 miracidia it resembles the sub-family Philophthalmince Looss. 



* stossich, M., " Brani di Elmintol. Tergestina III.," Bol. Soc. Ad. Trieste IX., 1886. 



t Niclioll, W. , "Parorchis aeantlius, the type of a new Genus of Trematodes," 

 Quart. Joiim. Mic. Sci., vol. 51, part ii., 1907. 



