336 _Necator americanus_: bursa of male. (After Looss) 458 337 _Syngamus kingi_: anterior end of male. (After Leiper) 460 338 _Syngamus kingi_: anterior end of female. (After Leiper) 460 339 Bursa of _Syngamus trachealis_. (Stephens) 461 340 _Physaloptera mordens_, Leiper, 1907. (After Leiper) 462 341 _Ascaris lumbricoides._ (From Claus) 463 342 Ovum of _Ascaris lumbricoides_ 463 343 Ovum of _Toxascaris limbata_ 466 344 Transverse section through the head part of _Belascaris cati_ from the cat. (After Leuckart) 466 345} 346} Male female of _Oxyuris vermicularis_ 468 347 _Oxyuris vermicularis_: egg freshly deposited 468 348 _Oxyuris vermicularis_: egg twelve hours after deposition 468 348A The male of _Echinorhynchus augustatus_ 476 348B Anterior portion of the female apparatus of _Echinorhynchus acus_. (After Wagener) 476 348C Egg of _Echinorhynchus gigas_. (After Leuckart) 477 348D The internal organs of the leech. (After Kennel) 480 348E _Hirudo medicinalis._ (After Claus) 481 349 _Leptus autumnalis._ (After Gudden) 485 350 _Leptus autumnalis._ (After Trouessart) 485 351 The kedani mite. (After Tanaka) 487 352 _Tetranychus telarius_ var. _russeolus_, Koch. (After Artault) 488 353 _Pediculoides ventricosus._ (After Laboulbène and Mégnin) 489 354 _Nephrophages sanguinarius_: male, ventral surface. (After Miyake and Scriba) 490 355 _Nephrophages sanguinarius_: female, dorsal aspect. (After Miyake and Scriba) 490 356 _Tydeus molestus._ (After Moniez) 491 357 _Dermanyssus gallinæ._ (After Berlese) 492 358 _Dermanyssus hirundinis._ (After Delafond) 492 359 _Ixodes ricinus_, male. (After Pagenstecher) 498 360 Female of _Ixodes ricinus_. (After Pagenstecher) 498 361 _Argas reflexus._ (After Pagenstecher) 506 362 _Argas persicus._ (After Mégnin) 507 363 _Tyroglyphus farinæ_: male. (After Berlese) 512 364 _Tyroglyphus longior_, Gerv. (After Fum. and Robin) 512 365 _Rhizoglyphus parasiticus_: male and female. (After Dalgetty) 514 366 _Histiogaster_ (_entomophagus_ ?) _spermaticus_. (After E. Trouessart) 515