66 BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



Male 15 mm. long by 550//, maximum width. Esophagus, including 

 bulb, 1.9 mm. long; esophagus 79/*, wide; bulb 370/* long by 210/* wide. 

 Preanal sucker 950/*. from tail end and measuring 140//, in diameter, 

 its posterior edge interrupted by a depression. Caudal alae (fig. 88) 

 originating just anterior to sucker and extending almost to tail end. 

 Cloacal aperture 640/*, from tail end. Twelve pairs of caudal 

 papillae, their position and relative size identical with those of 

 Heterakis isolonche: 2 pairs at the level of the sucker, 6 pairs adanal, 

 and 4 pairs postanal. Two spicules of almost equal length, 1.8 mm. 

 (the left spicule a few microns longer than the right spicule) ; the 

 width of the left spicule is 76/*, that of the right spicule 49/*. If 

 extruded, the spicules cross each other, a condition which is seen in 

 H. isolonche also, as figured by Lucet and Henry. 



Female 17 mm. long by 600/*, maximum width. Total esophagus 

 2.1 mm. long. Anus 1.2 mm. from tail end. Vulva 8 mm. from 

 head end; 2 prevulvar and 2 to 3 postvulvar papillae. Vagina very 

 long. Eggs 65 to 67/* by 35 to 40/*. 



Figs. 87-88. — 87, Heterakis isolonche. Male tail. After Linstow, 1006. 88, 

 Heterakis neoplastica. Male tail. After Wassink, 1917 



Life history. — Probably similar to that of H. gallinae (p. 54). 



Distribution. — Europe (Holland (Amsterdam)). 



This species is very close to H. -isolonche, but because of certain 

 morphological differences (size of worms, length of tail of both male 

 and female), and because of an apparent difference in pathogenicity 

 of the two nematodes, the present writer prefers to regard them as 

 distinct species at the present time. Spindle-cell sarcoma of the 

 pheasants listed above is attributed by Wassink to H. neoplastica, 

 whereas the nodular growths caused by H. isolonche have not been 

 shown to be of that nature. 



Since the above was written, Baylis (1925) has examined TVas- 

 sink's specimens and has come to the conclusion that this species is 

 identical with II. isolonche (p. 64). 



HETERAKIS LONGECAUDATA Linstow, 1879 



Hosts. — Franco/ in its gula/ris, Galloperdi.r x/xulicea, Lophophorus 

 impeyanus, Megacephalon -maleo, Tragopan satyra. 

 Location. — Ceca. 



