1922.] 



H. A. Baylis and R. Daubney : Parasitic Nematodes. 



291 



tip of the longer spicule is simple and straight. The lengths of the spicules are 

 238 mm. and 075 mm. respectively in a large specimen. The twelve pairs of caudal 

 papillae are arranged in the manner indicated by von Linstow, with the exception 

 that of the two pairs nearest to the posterior end one is situated laterally, the other 

 (slightly larger) ventrally, and both are at an equal distance from the tip of the tail. 

 In number and arrangement there is therefore no difference from H. papulosa. 



In the female, the tail is straight and gradually tapering, and measures i'i-i'2 

 mm. in length. There is a conspicuous pair of caudal papillae at about o*68 mm. 

 from the posterior end. The vulva is situated very slightly behind the middle of the 

 body (not in front of it, as stated by von Linstow), viz., at 37-475 mm. from the 

 posterior end. The vagina is long, and pursues a complicated course almost precisely 

 similar to that of H. papulosa. The terminal portion (ovejector) runs posteriorly 

 from the opening. The tube then makes a sharp turn anteriorly, then a curve to the 

 right and dorsally, then bends posteriorly, and from this point runs straight back to 

 a point about 1*5 mm. from the anus. Here it doubles upon itself, and at about 1 mm. 

 behind the val va gives off the two apparently opposed uteri. The greater part of the 

 coils of both ovaries lie in the anterior portion of the body, between the vulva and 

 the posterior end of the oesophagus. The ova are somewhat oblong, with a thick 

 shell, which is slightly dimpled at each pole. 

 They measure about 0*075 X 0*0425 mm. 



Perhaps the most reliable character by 

 which this form can be distinguished from H. 

 papulosa is the larger size of the preanal sucker 

 in the male — (outside diameter 0*06-007 mm - m 

 papulosa, 0*08-0*09 mm. in longecaudata). The 

 spicules are also a little longer, the right spicule 

 being longer than that of any other species 

 recorded in Galliform birds. The preanal sucker 

 is, as a rule, situated somewhat nearer to the 

 cloacal aperture than in H. papulosa, and the 

 caudal alae of the male are broader. On placing 

 examples of the two species side by side, the 

 males are fairly readily separable, but it would 

 be difficult to find characters by which the 

 females could be easily distinguished. 



Fig. 25. — Ascaridia perspicillum. 

 male : ventral view. 



Tail of 



Heterakis bosia, Lane, 1914. 



This interesting form, the male of which is 

 easily distinguished from that of other species 

 by the peculiar shape of its left spicule, was found 

 frequently in the crimson horned pheasant (Tragopan satyra). Although evidently 

 common, it does not appear to give rise to heavy infections. It occurred once in as- 

 sociation with H. longecaudata only, and once with both this species and H. isolonche. 



