24 ASCAROIDEA 



The validity of this genus appears extremely doubtful. Up 

 to the present the genotype is not characterized sufficiently 

 to enable its affinities with other genera to be determined. 



6. Thelandros Wedl, 1862. 



Lips bilobed. Buccal capsule absent. Oesophagus with 

 a very short pharynx and a posterior bulb. Lateral fields 

 each formed of a single row of very large cells with stellate 

 nuclei. Lateral alae present in male in some species, some- 

 times extending posteriorly as far as the cloaca. Tail of 

 male ends in a dorsal process. Caudal alae absent. Three 

 pairs of caudal papillae present, one of which is situated on 

 the ventral surface of the caudal process. A single spicule, 

 sharply pointed. Accessory piece absent. Tail of female 

 suddenly constricted behind the anus to form a terminal 

 spike. Vulva usually a little behind the middle of the body. 

 Uterine branches parallel. Eggs oval, not contauiing embryos 

 when laid. 



Hab. Alimentary canal of Lizards and Tortoises. 



Genotype : T. dlatus Wedl, 1862. 



Wedl, 1862, Sitz. k. Akad. Wiss., Wien, xliv, 470; Seurat, 

 1917, Arch. Zool. exp. et gen., Paris, Ivi, 412. 



7. Ozolairaus Dujardin, 1845. 



Head with " two lateral lobes," diverging distaUy. Mouth 

 elongated dorso-ventrally. Oesophagus long, composed of 

 two distinct portions ; the anterior short and stout, with a 

 fusiform swelling behind ; the posterior slender, ending in a dis- 

 tinct bulb behind. Tail of male short, finger-shaped, bluntly 

 rounded. A single long, stout spicule present. Tail of female 

 tapering. Vulva prominent, at about the posterior fourth of 

 the body. Female genital organs anterior. Eggs large. 



Hab. Intestine of Iguana. 



Genotype : 0. [Ascaris] megatyphlon (Rudolphi, 1819). 



Rudolphi, 1819, Entozoorum Synopsis, 47, 285 ; Dujardin, 

 1845, Histoire nat. des Helminthes, 145 ; Schneider, 1866, 

 Monographie der Nematoden, 120 ; v. Linstow, 1906, Arch. /. 

 Naturg., Ixxii, i, 254 (Oxyuris cirrata). 



8. Macracis Gedoelst, 1916. 



Mouth a vertical slit with lateral raised borders. Lateral 

 and submedian papillae present. Oesophagus very long and 

 slender, with three anteriorly directed valve-like cuticular 

 folds at its entrance, and with a large posterior bulb. Tail 

 in both sexes short and conical. Tail of male apparently 

 without alae, truncate ventrally, and with a short, dorso- 

 ventrally flattened, dorsal appendage, bearing a pair of 



