FILARIINAE 195 



relatively long, with long and wide alae, which have fine 

 transverse striations, and are continuous behind the extremity 

 of the tail. Caudal papillae variable in number and frequently 

 asymmetrical. Three or four pairs of preanal papillae and 

 six to eiglit pairs of postanal jjapillae. Spicules two, markedly 

 unequal, the right short and slender, the left several times 

 longer, divided into a proximal solid portion and a distal 

 portion with transversely striated alae. Tail of female blunt. 

 Vulva immediately behind the mouth, large and oval. Uterus 

 with long common trunk and two shorter branches. Eggs 

 with thick shell, containing embryos in utero. 



Hab. Adults in connective tissue of Vertebrates. Larvae 

 in blood-stream and lymphatic vessels of the same hosts. 

 Intermediate stages in blood-sucking Arthropods. 



Genotjrpe : F. viartis Gmelin, 1790. 



Miiller, 1787, Naturforscher, Halle, xxii, 64; Gmelin, 1790, 

 Sijstema Naturae, 13th ed., 3040; Stiles, 1907, U.S. Pub. 

 Health and Mar.-Hosp. Serv., Hyg. Lab. Bull. 34, 40; Hall, 

 1916, Proc. U.S. Nat. Mus., 1, 180; Seurat, 1920, Bull. 

 Soc. Hist. nat. Afrique du Nord, Alger, xi, 34 ; Momiig, 1924, 

 9th c& 10th Rep. Dir. Vet. Ed. and Res., Pretoria, 435. 



The type of the genus Filaria s.s. is held by Stiles & Hassall 

 (1905, 106) to be F. martis Gmelin, 1790. The identity of 

 this species is somewhat uncertain. Seurat (1920) and 

 Monnig (1924) have described forms which they assign to 

 F. martis, and their descriptions are, on the whole, in agree- 

 ment ; in neither case, however, was the material collected from 

 the tjrpe-host. We have been obliged to make use of these 

 specific descriptions in endeavouring to arrive at a satisfactory 

 diagnosis for the genus. 



2. Dirofilaria Railliet & Henry, 1911. 



Mouth without lip-like structures. Oesophagus slender. 

 Tail of male short and rounded, with slight alae. Caudal 

 papillae variable in number and asymmetrical. A preanal 

 group generally consisting of three to five pairs of voluminous 

 papillae, and two pairs of ventral adanal papillae present. 

 The postanal papillae consist usually of one large pair and 

 three smaller pairs close to the tip of the tail. Sj^icules 

 unequal and dissimilar, the longer terminating in a sharp 

 point, the shorter stout and spatulate. Tail of female short 

 and rounded. Vulva some distance from the anterior end 

 of the body. Viviparous. Embryos in blood-stream of host, 

 without " sheath." 



Hab. Blood-stream (chiefly right ventricle of heart) and 

 connective tissue of Mammals. 



Genotype : D. [Filaria'] immitis (Leidy, 1856). 



