558 



NEMATODE PARASITES OF THE DOMESTIC PIGEON^ 



given by Dujardin. The males are from 8.4 to 11.7 mm. long, and the anterior 

 part, occupied by the oesophag-us, is a little less than half the total length, in 

 a specimen 9.7 mm. long the proportions being -4.64 : 5.06. The females mea- 

 sure from 13 to 16.24 mm., an<l the relative lengths of anterior and posterior 

 portions 6.24 : 10. The diameter at the anterior end is about 0.006 mm. In 

 a male of 11.3 mm., the maximum diameter is 0.049, at the posterior extremity 

 0.028, at the base of the oesophagus 0.039, and about the middle of the oeso- 

 phagus 0.026 mm. The spicule. 1.44 mm. long, has an almost uniform width 

 of 0.007 mm., but is swollen at its anterior extremity into a hollow open knob 

 0.020 mm. wide (Text-fig. 13) . At its posterior extremity it is bluntly rounded 

 (Text-fig. 14). It is enclosed in a sheath which is very distinctly marked with 

 transverse striae at intervals of 0.002 mm. in the posterior 'part, the striae be- 



Text-fit;s.7-14. — Capi/laria colimihac. 

 Anterior end. (x 230). 8. Posterior end of female, (x 230), <;h. , amis; 9. Pos- 

 terior end of male, (x 230) ; 10. Kegion of junction of oesophaj^us (oe.) and 

 intestine (int.), (x 2.30). i6.,bacillary band; /., lumen of oesophagus; «., 

 nucleus; 11. Vagina and uterus, containing eggs, (x 140) ; 12. Egg in 

 terus. (x 230) ; 13. Anterior end of male spicule, (x 230) ; It. Posterior end 

 of spicule, in sheath, (x 230). 



coming fuier. and more indefinite towards the anterior end. In a few specimens 

 a considcralile portion of the sheath is everted, and the si)icule is projecting, but 

 in the majority the spicule is withdrawn some distance into the interior of the 

 body. It shows delicate. l>ut iiTegular, eross markings. The doacal aperture 

 is tierminal, and is |irovided with a small bursa-like stnicture, consisting of two 

 lateral lobular projections of the internal piotoida-smic substance, connected by a 

 delicate membrane. Travassos states it In lie tlircc-lolx'd, and in side view it has 

 this appearance (Text-fig. 9) . 



In the females the maximum diameter is 0.060 to 0.067 mm., at the ba,se of 

 the oesophagus 0.049 mm., middle of oesophagus 0.036 mm., and at posterior 

 extremity, which is bluntly rounded (Text-fig. 8), 0.030 mm. The anus is sub- 



