271] NORTH AMERICAN MONOSTOMES 53 



The genital glands show little development over that of the cercariae. 

 The ovary and testes are made out readily in the toto mount as well as the 

 cords of cells which are to differentiate into uterus, vagina, vas deferens 

 and cirrus. In more mature stages differentiation of the cirrus and vagina 

 is well started so that the relative length of the two organs can be deter- 

 mined. 



In the more mature specimens represented in figure 17 the genital 

 glands have made a tremendous growth and appear very much as in the 

 sexually active worm. The uterus, however, is less distinct and probably 

 still non-functional. It is in this stage that the vitelline glands make their 

 first appearance and here appear as single celled isolated follicles. The 

 ducts of these follicles cannot be traced so that it is impossible to determine 

 if the relation found by Faust (1918), namely that the vitellaria of Notoco- 

 tylids are composed of five inner and three outer portions, obtains in this 

 species. 



Of the seven larval Monostomata described from North America, viz. 

 Cer carlo, hyalocauda Haldemann 1842 Cercaria konadensis Faust 1918 

 Glenocercaria lucania Leidy 1877 Cercaria aurita Faust 1918 



Cercaria urbanensis Cort 1914 Cercaria robusta Faust 1918 



Cercaria pellucida Faust 1918 



the immature stages described above resemble more closely Cercaria ur- 

 banensis Cort (1914) than any other known monostome cercaria. Based on 

 the similarity of the excretory system, of the genital organs, on the pig- 

 mentation and on the late differentiation of the vitellaria, no trace of which 

 has yet been found in Cercaria urbanensis, it seems highly probable that 

 these forms can be actually connected. Hence while demonstration of the 

 life history by experimental methods has not at this time been given, it 

 seems justifiable to accept Cercaria urbanensis as the larval form of this 

 Notocotylid. 



NOTOCOTYLUS QUINQUESERIALIS (Barker and Laughlin) 



Syn: Monostoma sp. Stiles and Hassall 1894 



Notocotyle quinqueseriale Barker and Laughlin 1911 



Medium sized to large Notocotylids with wedge shaped body 2 . 5 to 

 4 mm long by . 66 to 1 . 33 mm in maximum width which is found at the 

 level of the ovary. Anterior end more or less pointed, posterior end 

 rounded. Dorsal surface smooth, convex, ventral concave, unarmed but 

 possessing five longitudinal rows of adhesive glands or papillae. Each 

 row containing from 16 to 18 distinct wart-like projections. Mouth sub- 

 terminal, spherical 200 to 450 M in diameter; esophagus short without phar- 

 ynx. Intestinal crura irregular in shape and size with short internal and 

 external diverticula. Genital pore between mouth and intestinal bifurca- 



