296 _Loa loa._ (After Leiper) 411 297 _Mf. loa_: in thick film, dried and stained with hæmatoxylin. (After Fülleborn) 413 298 _Acanthocheilonema perstans._ (After Leiper) 414 299 _Mf. perstans._ (After Fülleborn) 415 300 _Dirofilaria magalhãesi._ (After v. Linstow) 417 301 _Trichuris trichiura_ 420 302 _Trichinella spiralis._ (After Claus) 422 303 Isolated muscular fibre of a rat, invaded by Trichinella. (After Hertwig-Graham) 425 304 Calcified Trichinella in the muscular system of a pig. (After Ostertag) 426 305 Various phases of the calcification of Trichinella of the muscles 426 306 _Dioctophyme gigas._ (After Railliet) 432 307 Eggs of _Dioctophyme gigas_. (After Railliet) 432 308 _Metastrongylus apri._ (Stephens) 433 309} 310} _Trichostrongylus instabilis._ (After Looss) 434 311} 312} _Trichostrongylus probolurus._ (After Looss) 435 313} 314} _Trichostrongylus vitrinus._ (After Looss) 436 315} 316} _Hæmonchus contortus._ (After Ransom) 437 316} 317 _Mecistocirrus fordi._ (After Stephens) 439 318 _Ternidens deminutus._ (After Railliet and Henry) 440 319} 320} _Œsophagostomum stephanostomum_ var. _thomasi_. (After Thomas) 442 321} 322} _Œsophagostomum stephanostomum_ var. _thomasi_. (After Thomas) 444 323} 324} _Ancylostoma duodenale_, male and female. (After Looss) 446 325 _Ancylostoma duodenale_, showing ventral teeth. (After Looss) 447 326 _Ancylostoma duodenale_: diagrammatic representation of excretory system. (After a drawing by Looss) 448 327 _Ancylostoma duodenale._ (After Railliet) 449 328 _Ancylostoma duodenale_: bursa of male. (After Looss) 450 329 _Ancylostoma duodenale_: eggs in different stages of development. (After Looss) 451 330 _Ancylostoma duodenale_: larva. (After Leichtenstern) 452 331 _Ancylostoma duodenale._ (After Looss) 453 332 _Ancylostoma ceylanicum._ (After Looss) 456 333 _Ancylostoma braziliense._ (After Gomez de Faria) 456 334 _Necator americanus._ (After Looss) 457 335 _Necator americanus_: lateral view. (After Looss) 458