208 FILARIOIDEA 



f. Microfilaria Cobbold, 1880, et auctt. 



This is not a generic name, but a collective name for 

 immature Filariidae occurring in the blood-stream of 

 Vertebrates. 



g. Dermofilaria Rivolta, 1884. 



According to Railliet & Henry, the type and only species 

 (D. irritans) is the larva of Habronema sp. 



Rivolta, 1884, Oiorn. Anat., Fisiol. e Patol. Anim., Pisa, 

 xvi, 128; Railliet & Henry, 1915, Bull. Soc. Path, exot., Paris, 

 viii, 695 ff. 



Fam. 2. PHILOMETRIDAE nov. 



Body more or less elongated. Anterior end rounded, some- 

 times with a cuticular shield. Mouth simple, without lip- 

 like structures, but surrounded by six or eight papillae. 

 Anus sometimes absent in adult. Male, when known, much 

 smaller than female. Spicules two, equal, slender, finely 

 pointed. An accessory piece present. Vulva very incon- 

 spicuous or absent, and vagina rudimentary or absent, in 

 gravid females. Uterine branches directly opposed, forming 

 a continuous tube. Ovaries relatively very short, situated 

 at opposite ends of the body. Viviparous. Adults in body- 

 cavity, serous membranes or connective tissue of vertebrates. 



This family is doubtfully placed in the Order Filarioidea, 

 which contains some other atypical forms. The three genera 

 Philometra, Microjyleura and Dracunculus have certain peculiar 

 characters in common, and it is difficult to refer them to any 

 of the better-established families. A new subfamily, Micro- 

 pleurinae, within the family Filariidae, was tentatively pro- 

 posed by us (1922, 3Iem. Incl. Mus., vii, 319) to accommodate 

 Micropleiira. But in view of the great differences between 

 the female organs of this genus and those typical of the 

 Filariidae, the erection of a separate family seems a more 

 natural arrangement. A family Dracunculidae appears to 

 have been proposed by Leiper in 1912, to contain Dracunculus 

 medinensis . Of this species, however, the female only has 

 been at all adequately described, and it seems better to take 

 as the type of the family a genus which is better founded, and 

 of which both sexes, and more than one species, are known. 



1. Philometra Costa, 1846. 



Syn. Ichthyonema Diesing, 1861. 



Lateral fields broad. Mouth funnel-shaped, surrounded 

 by small papillae. Oesophagus relatively short, swollen 

 anteriorly, cylindrical posteriorly, and accompanied by a long 

 dorsal unicellular gland which opens into it by a narrow canal 



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