NEMATODE PARASITES OF BIRDS 381 



Life history. — Unknown; possibly similar to that of H. tricolor, 

 p. 376. 



Distribution. — Europe (Italy (Museum, Genoa and Cagliari) and 

 Austria (Museum, Vienna)). 



HYSTRICHIS ORISPINUS Molin, 1858 



Hosts. — Primary: Cygnus olor, Ibis falcinellus; secondary: Un- 

 known, probably fish, according to Jaegerskiold. 



Location. — Glands of pro vent riculus. 



Morphology. — Hystrichis (p. 375) : Head (fig. 442) distinctly 

 though gradually marked off from cervical region. Mouth at the 

 apex of a rectractile cone, large, with 4 short spines set crosswise. 

 Head end with closely-set straight triangular spines, 23 spines in 

 a circle, gradually becoming larger and more sparse posterior to 

 cervical region. 



Male unknown. 



Female 25 to 44 mm. long, 500y to 1 mm. wide. Posterior part of 

 body without spines but with dense transverse annulations. Anus 

 terminal. Vulva just slightly anterior to anus. Eggs not described. 



Life history. — Unknown; possibly similar to that of H. tricolor, 

 p. 376. 



Distribution. — Europe (Italy (Padua)). 



HYSTRICHIS VARISPINOSUS Jaegerskiold, 1909 



Most. — Primary : Mergus serrator; secondary: Probably fish, ac- 

 cording to Jaegerskiold. 



Location. — Not given; probably proventriculus. 



Morphology. — Hystrichis (p. 375) : Head (fig. 443a) only slightly 

 swollen, covered with 15 circles of small, closely-set strongly-bent 

 spines, the smallest of which are 27/* long, the largest 48/x long; 

 the highest number of spines in a circle is 52. Spines (fig. 443&) 

 of cervical region 88 to dO/x long, larger and less closely-set than 

 those of head; the highest number in a circle is 14 to 17, becoming 

 more scarce posteriorly and disappearing at a distance 7.2 mm. from 

 the head end. 



Specimen incomplete, sex undetermined, only the anterior region, 

 11 mm. long, present; maximum width 800/a, the width of head 400/*. 

 Esophagus 6 mm. long. 



Life history. — Unknown; possibly similar to that of II. tricolor, 

 p. 376. 



Distrib utiori. — Not given. 



HYSTRICHIS WEDLI Linstow, 1879 emended Jaegerskiold. 1909 



Synonyms. — Hystrichis, species Wedl, 1856; H. wwdlii Linstow, 

 187i)«. //. neglectus is possibly a synonym of this (see page 379). 



