HETERAKINAE 11 



Fam. 2. HETERAKIDAE Railliet & Henry, 1914. 



Parasitic forms. Polymyarian. Lips may be well defined, 

 or so reduced as to appear absent. A buccal capsule may be 

 present or absent. In the absence of a buccal capsule, the 

 anterior portion of the oesophagus is usually differentiated as 

 a pharynx. Except in Ascaridia, a posterior oesophageal 

 bulb is present. There is a more or less well-developed 

 preanal sucker in the male, with or without a chitinoid border. 

 Reproductive organs highly developed. Spicules usually 

 two (occasionally one or both may be imperfectly chitinized, 

 or absent). Vulva typically near the middle of the body, 

 occasionally posterior. 



Subfam. 1. HETERAKINAE Railliet & Henry, 1912. 



Lips well defined. Buccal capsule absent. Oesophagus 

 with a pharjaix and a posterior bulb, except in Ascaridia. 

 Preanal sucker nearly circular, with chitinoid border. Vulva 

 in the middle of the body or slightly anterior to it. Eggs 

 usually unsegmented when laid. 



1. Heterakls Dujardin, 1845. 



Syn. GanguleteraJcis hane, 1914; Gireterakis Jjane, 1917. 



Lips without " cordons." Oesophagus with a short pharynx 

 and a distinct subglobiilar bulla. Caudal alae of male 

 extremely well developed, and supported by pedunculate 

 papiUae. Spicules unequal or subequal. No accessory 

 piece. Branches of uterus either actually or apparently 

 opposed. Eggs with thick shell and unsegmented contents. 



Hab. Alimentary canal of Birds and Mammals. 

 Genotype : H. [Ascaris] papillosa (Bloch, 1782). 



Bloch, 1782, Abhandlung von der Erzeugung der Eingeiveide- 

 wiirmer, Berlin, 32; Dujardin, 1845, Histoire naturelle des 

 Helminthes, Paris, 136, 222 ; Travassos, 1913, Mem. Inst. Osw. 

 Cruz, Rio de Janeiro, v, 274; Lane, 1914, Ind. Journ. Med. 

 Res., ii, 656, 660, and 1917, iv, 754, 758, 764. 



2. Pseudaspidodera Bay Us & Daubney, 1922. 



Lips with "cordons," opening in -pairs at the interlabial 

 spaces, diverging and recurrent, ending blindly on outer surface 

 of lips. Oesophagus as in Heterakis, with a very short pharynx 

 and a well-developed posterior pyriform bulb. Caudal alae 

 of male well developed, and supported by pedunculate papillae. 

 Spicules unequal and dissimilar, the right long and slender, 

 the left short, stout and alate, with a barbed tip. No accessory 

 piece. Uterine branches opposed. Eggs thin-sheUed, with 

 a slight internal thickening at one pole. 



