548 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 57. 



caninum, from specimens taken from the small intestine of a dog at 

 Detroit, Michigan, August G, 1918, and made it the type of the genus 

 Hallum. Through the courtesy of Parke, Davis, and Co., the writer has 

 had the opportunity of examining tliree of Wigdor's specimens which 

 have been entered in the Bureau of Animal Industry Helminthologi- 

 cal Collections of the United States National Museum (No. 19028). 

 These collections also contain some specimens of C. lingua collected 

 from the intestine of Phoca vitulina by Dr. Albert Hassall, at the 

 National Zoological Park, Washington City, December 21, 1905. 

 (U.S.N.M. No. 4280.) The flukes from the dog (fig. 14) and the 

 seal (fig. 15) measure 0.88 to 1.14 mm. in length, 0.34 to 0.56 mm. in 

 width. The oral sucker is 70 to 110 [jl in diameter. Pharynx, 40 to 

 48 [JL in width by 50 to 60 ^ in length. Ventral sucker, 60 to 85 ^ in 

 transverse diameter ; genital sucker, 120 to 180 [x in transverse diame- 

 ter. The distance from the anterior end of the body to the bifurca- 

 tion of the intestine varies from 130 to 260 \}.. The testes measure 120 

 to 200 lA by 70 to 120 [a; ovary, 100 to 180 [x by 70 to 120 ^\ seminal 

 receptacle, 60 to 120 \i. in diameter. The eggs vary from 40 to 50 [x 

 in length and from 18 to 24 ^ in width. Wigdor evidently mistook 

 the genital sucker for the ventral sucker, and interpreted the latter 

 as the genital pore, also apparently confused the seminal vesicle and 

 the uterus in his description of Hallv/m caninum. 



Eyder (1884a) recorded the occurrence of encysted flukes in the 

 skin, gills, and mouth of cunners caught at Woods Hole, Massa- 

 chusetts, and Cape Breton, Nova Scotia. Linton (1900a, 19015) re- 

 corded similar parasites from cunners and tautogs. Stafford (1905(2) 

 named these worms Dernwcystis ctenoldbri. Linton more recently 

 (1915) has found these parasites in various other species of fish in 

 the Woods Hole region and has secured very good evidence that they 

 are immature stages of G. lingua which occurs among various fish- 

 eating birds in the same region. They not only correspond morpho- 

 logically with G. lingua but similar immature forms have been found 

 among adults of G. lingua in the intestines of the final hosts. 



CRYPTOCOTYLE JEJUNA (Nicoll, 1907) Ransom, 1920. 



Figs. 16, 17. 



1907. Tocotrema jejunum Nicoll, 1907/=, pp. 248, 257-259; 1909, p. 4S3, pi. 



10, figs. 20, 21. 

 1920. Cryptocotyle jejuna (Nicoll, 1907) Ransom, 1920 (the present paper). 



Specific diagnosis. — Gryptocoiyle : Maximum length about 1.8 mm., 

 maximum width varying from one-eighth to one-third the length. 

 Oral sucker about 45 [x in diameter. Pharynx, 38 [x long by 18 ^ 

 wide ; prepharynx somewhat shorter than pharynx. Average length 

 of esophagus about 100 jx, nearly one-twelfth the body length. Geni- 



