_Trichostrongylus_, Looss, 1905 434 _Trichostrongylus instabilis_, Railliet, 1893 434 _Trichostrongylus probolurus_, Railliet, 1896 435 _Trichostrongylus vitrinus_, _Looss_, 1905 435 Genus. _Hæmonchus_, Cobb., 1898 436 _Hæmonchus contortus_, Rudolphi, 1803; Cobb., 1898 436 Genus. _Nematodirus_, Ransom, 1907, emend. Railliet, 1912 438 Sub-genus. _Mecistocirrus_, Railliet, 1912 438 _Mecistocirrus fordi_, Daniels, 1908 438 Sub-family. _Ancylostominæ_, Railliet, 1909 438 Group. _Œsophagostomeæ_, Railliet and Henry, 1909 439 Genus. _Ternidens_, Railliet, 1909 439 _Ternidens deminutus_, Railliet and Henry, 1905 440 Genus. _Œsophagostomum_, Molin, 1861 441 _Œsophagostomum brumpti_, Railliet and Henry, 1905 441 _Œsophagostomum stephanostomum_ var. _thomasi_, Railliet and Henry, 1909 443 _Œsophagostomum apiostomum_, Willach, 1891 444 Group. _Ancylostomeæ_, Railliet and Henry, 1909 445 Genus. _Ancylostoma_, Dubini, 1843, emend. Looss, 1905 445 _Ancylostoma duodenale_, Dubini, 1843 445 _Ancylostoma ceylanicum_, Looss, 1911 456 _Ancylostoma braziliense_, Gomez de Faria, 1910 456 Group. _Bunostomeæ_, Railliet and Henry, 1909 456 Genus. _Necator,_ Stiles, 1903 457 _Necator americanus_, Stiles, 1902 457 _Necator exilidens_, Cummins, 1912 459 Ancylostomiasis 459 Group. _Syngameæ_, Railliet and Henry, 1909 459 Genus. _Syngamus,_ von Siebold, 1836 459 _Syngamus kingi_, Leiper, 1913 459 Family. _Physalopteridæ_ 460 Genus. _Physaloptera_, Rudolphi, 1819 460 _Physaloptera caucasica_, v. Linstow, 1902 461 _Physaloptera mordens_, Leiper, 1907 461 Family. _Ascaridæ_, Cobbold, 1864 461 Sub-family. _Ascarinæ_ 461 Genus. _Ascaris_, L., 1758 461 _Ascaris lumbricoides_, L., 1758 463 _Ascaris_ sp. 465