28 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 50. 



Location. — Duodenum, . 



Locality. — United States (Nebraska). 



This parasite, described in a paper by Barker (1915), is reported, 

 as noted, from the duodenum, a most unusual location for a worm 

 of this genus. His indicated magnifications do not agree with the 

 text. 



imm 



Fig. 31.— Trkuurls opaca. Female. Aftee Barker, 1915. 



TRICHURIS OVIS (Abildgaard, 1795) Smith, 1908. 



Synonyms. — Trichocephalus ovis Abildgaard, 1795 ; Triclwcephalus 

 aifinis Kudolphi, 1802; Mastigodes aifinls (Rudolphi, 1802) Zeder, 

 1803. 



Specific diagnosis. — Trichuris (p. 20) : Head 10 to 22 fi in diameter, 

 according to place of measurement, and sometimes provided with 

 two lateral vesicular swellings. Bacillary band originates about 80 

 fi posterior of the anterior end and is about 140 fi wide near the union 

 of the two parts of the body. The marginal rods of the bacillary 



