420 J- Stafford, 



breacitli and tlien [tapers off to a point; in many contracted indi- 

 viduals it tapers from the sncker backwards. The large ventral 

 sucker. 70 and '75 mm in length and breadtli, will alone distin- 

 o-uisli it from everj^ other species, with tlie possible exception of 

 No. 4. Even here, wlien we tliink of tlie sncker compared witli tlie 

 length of tlie animal, we find that in No. 5 it is considerably tlie 

 larg:er. In living worms tlie sucker, especially wlien flattened 

 against any object, may considerably exceed the dimensions given 

 for the averag-e size of animal. It is about 2b to 266 times 

 the size of the mouth sucker in preserved animals, and these g-ive 

 the most constant proportions for the reason that in them it is 

 never at maximum extension, but in living- animals it varies much 

 more in shape tlian the mouth- sncker does. It Stands out from the 

 body like a broad bowl flxed by a narrow base and with the free 

 edg-e curved in. 



The only point in which this species particularly resembles the 

 European one {G. cygnoides Zeder) is in the possession of 9 testes, 

 4 011 the one side and 5 on she other. So distinct a character is 

 this that G. cygnoides and G. ampUcava should be associated as a 

 sub-g-roup and separated from the rest — perhapes under a dif- 

 ferent g-eneric name. 



The intestinal cseca are, in the middle part of their course, 

 pressed far apart by the interposed g-enital organs. Of these the 

 first in Order behind the sucker is the vitellarium, consisting of 

 two lateral bunches of eight or ten follicles each, connected by the 

 transverse duct which opens at its middle througdi the vitelline re- 

 servoir into the oviduct. The ovary, as in the other species, may 

 be left or right — in 25 mounted specimens it is left in 13 and 

 right in 12 — and is of irregulär shape, consisting- of three to five 

 main lobes which may themselves bear two or three notches each. 

 The testes form two parallel rows lying behind the ovary and 

 between the cseca — five in a line with the ovary and four on 

 the opposite side. They are likewise notched along- the sides, 

 presenting' an irregularly lobed appearance. Between the two 

 series as well as between the testes of each series and along the 

 intestines at each side of the body are the coils and folds of the 

 Uterus. The distal part of the latter accompanies the larg-e vesicula 

 seminalis and opens at the common genital pore midway between the 

 ventral sucker and the bifurcation of the intestine. The habitat of 



