*C. Nemathelminthes* 360 Class. NEMATODA 360 Anatomy of the Nematodes 360 Development of the Nematodes 371 CLASSIFICATION OF THE NEMATODA. Family. _Anguillulidæ_, Gervais and van Beneden, 1859 374 _Angiostomidæ_, Braun, 1895 374 _Gnathostomidæ_ 374 _Dracunculidæ_, Leiper, 1912 374 _Filariidæ_, Claus, 1885 374 _Trichinellidæ_, Stiles and Crane, 1910 375 _Dioctophymidæ_ 375 _Strongylidæ_, Cobbold, 1864 375 _Physalopteridæ_ 375 _Ascaridæ_, Cobbold, 1864 375 _Oxyuridæ_ 375 THE NEMATODES OBSERVED IN MAN 376 Family. _Anguillulidæ_ 377 Genus. _Rhabditis_, Dujardin, 1845 377 _Rhabditis pellio_, Schneider, 1866 377 _Rhabditis niellyi_, Blanchard, 1885 378 _Rhabditis_, sp. 378 Genus. _Anguillula_, Ehrenberg, 1826 379 _Anguillula aceti_, Müller, 1783 379 Genus. _Anguillulina_, Gervais and Beneden, 1859 379 _Anguillulina putrefaciens_, Kühn, 1879 379 Family. _Angiostomidæ_, Braun, 1895 379 Genus. _Strongyloides_, Grassi, 1879 379 _Strongyloides stercoralis_, Bavay, 1877 380 Family. _Gnathostomidæ_ 384 Genus. _Gnathostoma_, Owen, 1836 384 _Gnathostoma siamense_, Levinson, 1889 384 _Gnathostoma spinigerum_, Owen, 1836 385 Family. _Dracunculidæ_, Leiper, 1912 385 Genus. _Dracunculus_, Kniphoff, 1759 385 _Dracunculus medinensis_, Velsch, 1674 386 Genus (of _Crustacea_). _Cyclops_, Müller, 1776 390 Family. _Filariidæ_ 390 Sub-family. _Filariinæ_ 390 Genus. _Filaria_, O. Fr. Müller, 1787 390