Introduction to Animal Morphology. 185 



has been found in the human bladder. 7. Tropidocereidae — 

 male slender ; female sub-globose, with four longitudinal 

 bands ; neck with two basilar spines. 8. Cheiracanthidae — 

 body armed as far as the middle with pointed lateral lamellae ; 

 head bristled, two-lipped ; penis not sheathed ; in cats, tigers, 

 alligators, &c. 9. Physalopteridae — males with a winged 

 tail-vesicle filled with a clear fluid ; mouth bilabiate, papil- 

 lose outside, toothed within ; in alligators and Mammals. 



10. Ascaridse — mouth with three labial lobes, and sometimes 

 touch papillae ; stomach often with teeth. The penis in 

 Ascaris is thread-like, with a two-leaved sheath. A. lumbri- 

 coides is the common human round worm, also in the orang, 

 swine, &c. ; 5-11" long ; tapering to each end ; each lip has 

 many (200) papillae ; the females are largest, and, as in other 

 species, the most numerous ; the vagina opens at the anterior 

 third. A. mystax, of the cat, is winged at its head. A. acus, 

 of the gar-pike, has linear wings. A. heteroptera has inequi- 

 lateral wings. Haligmus has a spiral, sheathless penis. 



1 1 . Oxyuridse — long, with naked or spiny tails ; mouth ter- 

 minal, papillose, or lobate ; teeth pharyngeal (Passalurus), 

 oesophageal (Pharyngodon, with no penial sheath), or at the 

 junction of the pharynx and oesophagus (Heterakis). Oxyuris 

 has no teeth ; the tail is acute in the female, papillose in the 

 male. O. vermicularis is the human thread-worm. Cosmo- 

 cerca is four-lipped, and has a ventral horny plate. Tachy- 

 gonetria is viviparous. 12. Ptychocephalidas — thread-like; 

 head sub-globose, with five radiating folds ; oesophagus with 

 three horny grooves; in beetles. 13. Filaridae — hair-like; 

 mouth round ; penis thread-like, with one or two leaf-like 

 sheaths. Filaria Medinensis, the Guinea worm, is viviparous, 

 and begins life as a form like Urolabes ; pierces the skin of 

 bathers, then develops in the cellular tissue, and may attain 

 the length of several feet. F. capucinus has been found in 

 American monkeys. F. lentis in the human eye. F. Loa in 

 the eye of a Negro. Filaroides, of the polecat, is ringed. 

 Gongylonema, of the mouse, has in front a longitudinal 

 series of bulbilli. 14. Liorhynchidae — mouth in the centre 

 ■of a protractile tube; found in fishes. 



Sub-order 4. Acrophalli — proctuchous ; penis terminal. 



