NEMATODE PARASITES OF BIEDS 



363 



cording to Mueller, serving not only as a gubernaculum for the 

 longer spicule but also as a clasping organ. 



Female 5 to 6 mm. long by 200/i wide. Vulva (fig. 424 g) slightly 

 prominent, situated slightly posterior to middle of body, dividing 

 the body length in ratio of 4 : 3. Anus 100/* from posterior extremity ; 

 body narrowed into a conical point posterior to anus (fig. 424 /'). 

 Eggs 40/a long by 33/*. wide, embryonated, bluntly oval, the shell 

 10/* thick. 



Life history. — Unknown. 



Distribution. — Not given (Germany?). 



This species should certainly be in the same genus with A. bilabiata. 

 Mueller evidently did not know that Diesing had made a new genus 

 for the species bilabiatus as he calls it Ancyracanthus bilabiatus and 



Fig. 424. — Ancyracanthopsis bihamata. a and b, Head end ; c and d, male 

 tail; e, spicule; f, female tail; g, vulva. After Mueller, 1897 



says his species is very close to it. As in it, his species does not have 

 the " immersionssystem," a complicated system of connections be- 

 tween the pinnate appendages and cervical sacs; Mueller made 

 numerous longitudinal sections of the appendages. This system is 

 present in the genus Ancyracanthus but apparently lacking in 

 Ancyracanthopsis. The host difference between the two genera would 

 also throw bihamatus into Ancyracanthopsis, the latter having been 

 made for bird forms and Ancyracanthus left for fish and reptile 

 forms. 



Family GNATHOSTOMIDAE R. Blanchard, 1895 



Synonyms. — Cheiracanthidea Diesing, 1861 ; Oxyuridae Railliet 

 and Henry, 1916, in part; Heterakidae Seurat, 1918, in part. 



Family diagnosis. — Spiruroidea (p. 162) : Mouth with 2 large tri- 

 lobed, lateral lips, a longitudinal tooth-like ridge on their inner sur- 

 face, meeting the one on the opposite side. Male with caudal alae 

 more or less well-developed ; two spicules. Female with vagina an- 



