NEMATODE PARASITES OF BIRDS 361 



The cuticle is inflated in the posterior part of the body, into a muff- 

 like formation, from which projects the caudal extremity, with a 

 length of 180y. Anus 225/* from posterior extremity; tail digitiform, 

 rounded at the end and carrying at the point a small rounded spike. 

 Vulva a short distance in front of anus. Ovejector similar to that of 

 M. inermis; vestibule turnip-shape, 1.6 mm. long, containing a large 

 number of eggs ; sphincter short ; trompe Y-shaped ; combined length 

 of vestibule, sphincter and unpaired trompe 2.6 mm. Uterus 95^t in 

 diameter, filled with eggs disposed in 3 linear rows; receptaculum 

 seminis not delimited. Oviducts short (300/*) ; ovaries slender, fili- 

 form, 6.5 mm. long. Eggs 50/x long by 30/* wide, embryonated at 

 maturity, thick-shelled, oval, flattened on one face. 



Larva 2.3 mm. long by 70/* wide. Buccal capsule 20/x long; 

 pharynx 320/i. long, surrounded in the middle by nerve ring ; esopha- 

 gus 600/x long. Cervical papillae 210/x from the anterior extremity. 

 Tail pointed, 170/a long. 



Life history. — Probably similar in a general way to that of T. /?.<?- 

 sispina (p. 343). 



Distribution. — Africa (Algeria) . 



Family ANCYRACANTHIDAE Railliet, 1916 



Family diagnosis. — Spiruroidea (p. 162) : Head with 4 pinnate, 

 posteriorly directed appendages, set crosswise. Male with caudal 

 extremity coiled in spiral; caudal alae present, provided with papil- 

 lae. Female with vulva posterior to middle of body ; 2 uteri. 



Parasitic in digestive tract of fish, reptiles, and birds. 



Type-genus. — Ancyracanthus Diesing, 1838. 



Genus ANCYRACANTHOPSIS Diesing, 1861 



Generic diagnosis. — Ancyracanthidae (p. 361) : Body capillary. 

 Head continuous with body, armed with 4 pinnate, posteriorly di- 

 rected appendages, set crosswise. Mouth terminal, with 2 small 

 papillae or lips. Male with caudal extremity coiled twice in spiral, 

 with 2 alae provided with papillae. Female with caudal extremity 

 which may be spirally twisted, apex obtusely conical. Vulva situated 

 posterior to middle of body. 



Parasitic between the tunics of the gizzard of birds. 



Type-species. — Ancyracanthopsis bilabiata (Molin, 1860) Diesing, 

 1861. 



Diesing created this genus to remove from Ancyracanthus the one 

 species at that time reported from a bird, all the others being fish or 

 reptile parasites. At a later date Mueller, in describing a second 

 species from a bird, states that the bird forms do not have the com- 

 plicated " immersionssystem " that is present in the species found in 

 reptiles and fish (see discussion under A. bihamata. p. 362). 



