269] NORTH AMERICAN MONOSTOMES 51 



the writer feels justified under Article 32 of the International Rules of 

 Zoological Nomenclature in accepting with Kossack, Ward and others the 

 older name Notocotylus. 



This genus is up to the present represented in America by a single spe- 

 cies Notocotylus quinqueserialis (Barker and Laughlin). Altho Barker 

 (1916) would place Monostomum qffine Leidy in this group, his determina- 

 tion seems to be unwarranted on the basis of the description of Leidy which 

 shows distinct anatomical differences namely a small pharynx, echinate 

 penis, a well marked excretory canal traceable to the beginning of the 

 oviduct, and sub-pyriform eggs prolonged at one pole only. In addition to 

 the anatomical differences Monostomum affine was found parasitic in the 

 gall bladder and gall ducts of Fiber zibethicus whereas Notocotylus has been 

 taken only from the intestine and ceca of the muskrat and water birds. 



NOTOCOTYLUS URBANENSIS (Cort 1914) 



[Figures 12, 14, 17, 18, 19] 

 Syn: Monostoma sp. Stiles and Hassall 1894 



Medium sized worms 2.5 to 3 . 5 mm long by 0. 5 to 1 mm wide, having 

 three rows of ventral glands each row containing 13 to 14 glands. Oral 

 sucker strongly muscular 112 to 153 n followed by a short esophagus with- 

 out pharynx; intestinal crura provided with numerous short diverticula 

 both externally and internally. Genital pore just posterior to intestinal 

 bifurcation. From this point the cirrus pouch extends caudad to the end 

 of the first body third or a little beyond this level. Vagina one-half the 

 length of the cirrus. Usually about ten uterine loops anterior to the most 

 anterior part of the vitellaria which as in other species of the genus lie 

 lateral to the ceca and extend from the middle of the body to the lobed 

 testes in the posterior end. The irregularly lobed ovary is situated between 

 the testes and is separated from them by the crura. Eggs numerous pos- 

 sessing two long polar filaments. Eggs without filaments measure 20/* in 

 length, and are approximately one-half that in width. 



Habitat: Intestine Host: Dafila acuta 



Locality: Maryland Collector: A. Hassall 



Date: January, 1893 No. 5772 U.S.N.M. 



Habitat: Cecum Host: Fiber zibethicus 



Locality: Maryland Collector: A. Hassall 



Date: June 23, 1892 No. 5769 & 5770 U.S.N.M. 



Habitat: Intestine Host: Aix sponsa 



Locality: Maryland Collector: A. Hassall 



Date: August, 1893 No. 5771 U.S.N.M. 



Notocotylus urbanensis agrees with Notocotylus attenuatus in size and 

 form, and in the relative length of the cirrus pouch and vagina. With 

 respect to the number of papillae in each row it conforms more closely 



