ACUARIINAE 221 



so that it becomes spindle-shaped or even subglobular. The 

 oesophageal region and the tail remain normal. 



Hab. Proventriculus of Birds ; males free in lumen, females 

 in nodules in wall. 



Genotype : T. paradoxus Diesing, 1835. 



Diesing, 1835, Med. Jahrb. k. k. Osterr. Staates, Wien, xvi, 

 83, 93 ; Travassos, 1914, Mem. Inst. Oswaldo Cruz, Rio de 

 Janeiro, vi, 155; 1915, Braz. Med., Rio de Janeiro, No. 38, 

 297 ; 1919, Mem. Inst. Oswaldo Cruz, xi, 71 ; Skrjabin, 1910, 

 Ann. Mus. Zool., Petrograd, xx, 526. 



Travassos (1915) proposes to divide the genus Tetrameres 

 into two subgenera, Tetrameres and Microtetrameres. In the 

 former the male is provided with spines along the lateral lines, 

 while in the latter the spines are absent and the long spicule 

 is of excessive length. This subdivision seems to us to be 

 unnecessary. If it were desired to retain the subgenera, the 

 name Tetrameres would have to be changed in accordance with 

 the generic name. The family Tetrameridae, within the 

 Spiruroidea, was proposed by Travassos (1914) for the recep- 

 tion of the genus Tetrameres. We have placed this genus in 

 the Spiruridae, but hesitate to create a special subfamily to 

 contain it. 



6. Crassicauda Leiper & Atkinson, 1914. 



Cuticle thick, transversely striated, sometimes raised at one 

 point into a swelling or holdfast. Mouth without lips, but 

 with four submedian papillae and two lateral papillae. The pulp 

 of the lateral papillae divides into two processes, one exterior 

 and the other terminating within the buccal cavity. A buccal 

 capsule present. Mouth and buccal capsule laterally compressed. 

 Oesophagus with a relatively short, feebly-muscular anterior 

 portion and a very long posterior portion which is partly 

 muscular, partly glandular, and may be doubled upon itself 

 several times. Tail of male laterally compressed and spirally 

 coiled, with a ventral groove behind the cloaca, within which 

 on either side there is a somewhat irregular row of papillae. 

 Spicules smaU and unequal, or absent. Anus terminal in 

 female. Vulva in a constricted portion of the body, just in 

 front of the knob-like posterior extremity. Vagina short. 

 Uterine branches parallel, running forwards. Ova thick- 

 shelled, containing embryos when laid. 



Hab. Urino-genital system or, rarely, other parts of the 

 body of Cetacea. 



Genotype : C. [Filaria] crassicauda (Creplin, 1829) nee 

 Leiper and Atkinson, 1914 and 1915. 



Creplin, 1829, Nova Acta Phys.-Med. Acad. Nat. Curios., 

 Bonn, xiv, 874; Leiper and Atkinson, 1914, Proc. Zool. Soc, 



