DIPLOTRIAENINAE 203 



We have placed this genus at the end of the subfamily 

 Filariinae, although its position is rendered somewhat 

 uncertain by the statement of Railliet & Henry (1910) that 

 lateral alae are present. 



Subfam. 2. DIPLOTRIAENINAE Skrjabin, 1916. 



Head provided laterally with a pair of trilobed chitinoid 

 epaulette-like structures ("tridents"), which may be super- 

 ficially situated or more deeply, at the sides of the oesophagus. 

 Oesophagus typical. Spicules unequal and dissimilar. Adults 

 in connective tissue and serous cavities of Birds and Reptiles. 



1. Diplotriaena Railliet & Hem-y, in Henry & O'Zoux, 1909. 



Syn. Triplotriaena Connal, 1912. 



Head with six inconspicuous papillae (two lateral, four 

 submedian). Mouth small, circular. Oesophagus with a 

 short, slender, anterior, muscular portion and a stouter, very 

 long, posterior portion. Tail of male short, bluntly rounded 

 or truncate. Up to six pairs of small, sessile, caudal 

 papillae present. Spicules unequal, dissimilar, the left longer 

 and straight, the right shorter and spirally twisted. Vulva 

 in oesophageal region. Common trunk of uterus long. 

 Uterine branches at first parallel, then divergent. Eggs 

 thick-shelled, containing embryos in utero. Embryos occur in 

 blood-stream of host. 



Hab. Connective tissue of Birds. 



Genotype : D. [Filaria] tricuspis (Fedchenko, 1874). 



Fedchenko, 1874, Izviest. Imp. Obsh. Liub., etc., Moscow, 

 X, 60; Hem-y & O'Zoux, 1909, Bull. Soc. Path, exot., Paris, 

 .ii, 547 ; Seurat, 1915, Novit. ZooL, London, xxii, 17 ; Skrjabin, 

 1917, ParasitoL, ix, 471. 



2. Dicheilonema Diesiug, 1861. 



Syn. Contortospiculum Skrjabin, 1915. 



Mouth with two strong, prominent, lateral lip-like structures. 

 Head with two lateral and four double submedian papillae. 

 The posterior lobes of the " tridents " are much expanded. 

 Oesophagus with a short, narrow, anterior portion and a 

 stouter, very long, posterior portion. Tail of male with broad 

 alae supported by five or six pairs of pedunculate preanal 

 papillae and a varying number of pairs of postanal papillae. 

 Spicules unequal and dissimilar ; the proximal end of each 

 swoUen and clubbed, the distal half of the longer spicule 

 with an aliform expansion, the alae being rolled so as to form 

 a more or less closed tube, and with serrated edges. The 



