542 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



head is without papillae. Milks agrees with Neumann's description 

 of it as having two or three prominences or concentric lips, behind 

 which there are three papillae; according to Blumberg, the head bears 

 several papillae; according to Rabe, the mouth is surrounded by two 

 or three concentric folds, and near it there is one large eminence with 

 two smaller ring-shaped ones behind it) . The male has two unequal 

 yellowish spicules. (The inequality is not very great, as is the case 

 in species of the genus Filaria, since the type species of Oslerus 

 has spicules 48 and 56 fx long) . The posterior extremity of the male is 

 bluntly rounded, according to Rabe; somewhat pointed, according to 

 Osier; or somewhat pointed and slightly bent, according to Blumberg. 

 The female has a rounded tail end and the vulva is very close to the 

 anus (Rabe says just anterior to the anus, and Milks agrees with this; 

 Blumberg says 20 n anterior of the anus; and Osier says the anus and 

 vulva open to the exterior by a cloaca, or common channel). The 

 worms are ovoviviparous, the eggs hatching in the uterus, giving rise 

 to embryos which are blunt anteriorly and pointed posteriorly. 



The only known species occurs in the trachea and bronchi, and 

 apparently in the pulmonary parenchyma also, of the dog. 



Type species. — Filaria osleri Cobbold, 1879. 



The fact that this worm is ovoviviparous would suggest an affinity 

 with the Filarioidea. Its location in the lining of the respiratory tract 

 and the presence of the vulva directly in front of the anus excludes it 

 from the Filarioidea and relates it to the Spiruroidea near the Gongyl- 

 oneminae, which also have the vulva close to the anus. The fact that 

 it is ovoviviparous does not fit in well with the known members of 

 the Spiruroidea, but as there is more or less variation in the matter of 

 depositing eggs or bearing embryos within the limits of the larger 

 groups, this may be regarded as a variation within the reasonable 

 definition of the superfamily, the worm being regarded as an aberrant 

 development. 



This worm is designated as Oslerus osleri (Cobbold, 1879) Hall, 1921, 



The other species for which a new generic name is necessary is 

 Strongylus rubidus Hassall and Stiles, 1892, from the stomach of 

 swine. 



This species belongs in the superfamily Strongyloidea, but not in 

 the genus Strongylus. This genus in the old extended sense contains 

 at present over 350 specific names and variations of one sort and 

 another, and has been restricted in its accurate meaning to forms 

 congeneric with its type species, Strongylus equinus Mueller, 1784, 

 from the large intestine of Equidae. The superfamily Strongyloidea 

 is usually divided into the families Strongylidae, Trichostrongylidae, 

 and Metastrongylidae. The genus Strongylus is the type genus of 

 the family Strongylidae. Strongylus rubidus belongs in the family 

 Trichostrongylidae. It has affinities with such genera of Tricho- 



