BUREAU OB" ANIMAL INDUSTRY. 



List of genera (chiefly neniatodes) originally published with a single species Continued. 



Stephanurus Diesing, 1839a (denlatus). 

 Stomachida Pereboorn, 1780 (vermis). 

 Streptogaster Cobb, 1898 (papillatus). 

 Streptostoma Leidy, 1849 (agile). 

 Strongylacantha van Beneden, 1873 (gly- 



cirrhiza). 

 Slrongyloides Grassi, 1879 (inlestinalis= 



stercoralis) . 

 Strongylus Mueller," 1780," 1784 



(equinus). 



Subulura Molin, 1860 (acutissima) . 

 Syngamus Siebold, 1836 (trachealis) . 

 Syncecnema Magalhaes, 1905 (fragile). 

 Synplecta Leidy, 1851 (pendula). 

 Syringolaimus de Man, 1888 (striatocau- 



datus). 



Tachygonetria Wedl, 1862 (vivipara). 

 Tanqua R. Blanchard, 1904 (tiara). 

 Teratocephalus de Man, 1876 (terrestris) . 

 Terschellingia de Man, 1888 (communis). 

 Tetracheilonema Diesing, 1861a (quadrtta- 



biatum ) . 



Tetradenos Linstow, 1904 (tiara). 

 Tetrameres Creplin, 1846 (paradoxus). 



Thalassironus de Man, 1889 ( britannicus) . 

 Thalassoalaimus de Man, 1893 (tardus). 

 Thelandros Wedl, 1862 (alatus). 

 Thelastoma Leidy, 1849 (attenuatum) . 

 Thelazia Bosc, 1819 (rhodesii) . 

 Trefusia de Man, 1893 (longicauda) . 

 Tricheilonema Diesing, 1861a ( megalochila). 

 Trichina Owen, 1835 (spiralis). 

 Trichinella Railliet, 1895 (spiralis). 

 Trichoderma Greef, 1869 (oxycaudata) . 

 Trichodes Linstow, 1874 (crassicauda) 

 Trichonema Cobbold, 1874 (arcuata). 

 Trichuris Rcederer & Wagler, 1761, 1762 



(trichiura). 



Tricoma Cobb, 1894 (cincta) . 

 Tropidocerca Diesing, 1851a (paradoxa). 

 Tropisurus Diesing, 1835 (paradoxus). 

 Tylolaimophorus de Man, 1880 (typicus). 

 Tylopharynx de Man, 1876 (striata). 

 Uracanthus Diesing, 1861 (brevispinosus). 

 Urolabes Carter, 1858 (palustris). 

 Vena Gallandat, 1773a (medinensis). 

 Xyo Cobb, 1898 (histrix). 



Despite the self-evident character of the principle involved, a few 

 genera of this category have later come to be used in a sense entirely 

 different from that in which they were originally intended, as indicated 

 by reference to the type. The explanation of this is clear. Authors 

 have placed additional species in a given genus of this kind; then the 

 species have later been distributed in two or more genera, and the 

 original species has been transferred to some other than the original 

 generic name. As an example of this kind among the nematodes, 

 Strongylus may be mentioned. It is clear that this species was origi- 

 nally (Mueller, 1780, pi. 42, figs. 1-12) based upon Strongylus equinus. 

 It is true that in his text Mueller later (1784, 8) says "Congenerem 

 valde similem claris. Otto Fabricius in intestinis ouium nuper reperit," 

 but the species (S. ovinus) in question can not come into consideration 

 as type of Strongylm, for not only does 8. ovinus not appear to have 

 been described or figured in 1780. but it is clear that Mueller based 

 his genus upon S. equinus. Other species were afterwards added to 

 Strongylus, and Rudolphi (1809a, 35), in suggesting a division of 

 Strongylus, placed both S. equinus and S. ovinus in the Sclerostoina 

 group, thus indicating a transfer of Strongylus s. st. to the newer 

 forms, for which, by the way, another generic name ( Uncinaria) was 

 at that time known to Rudolphi to be available. De Blainville (1828a) 

 carried out Rudolphi's suggestion, definitely separating the two genera, 

 and the generic name Strongylus is now generally used for a group of 



