BY VERA IRWIN-SMITH. 317 



metry of the lips, the mouth is not quite terminal in position ; but as the lips are 

 lateral, and the lower lip is on the left side, the opening is towards the side 

 instead of dorsal. A close study of Froelich's figures and Dujardin's description 

 suggests that this is also the ease in B. cristata. Dujardin himself shows some 

 doubt and confusion about the position of the mouth, and queries his own state- 

 ment in regard to it. His confusion is evidently due to his assumption that the 

 spine row is dorsal, and the vulva to one side of it, "situee lateralement, ou 

 presque a la face dorsale (?)." The lips, then, which are lateral in relation to 

 the vulva, are taken to be dorsal and ventral in position. But it is probable 

 that the vulva was in the normal, ventral position and, in that case, the spine 

 row and the lips would occupy the same relative positionsi to it as they do in R. 

 ddsparilis. 



Dujardin does not mention any elaborate buccal armature at the base of 

 the capsule, such as is present in the more recently described species, and nothing 

 of th-e kind has been observed in B. disparilis. It is unfortunate that the material 

 available does not permit of a clear determination of all the details of the mouth 

 structure. But the relationship to Physaloptera is evident, and it seems probable 

 that Bictularia disparilis and, perhaps, R. cristata represent transition forms be- 

 tween the simple Physaloptera type and the more highly specialised types of Bic- 

 tularia with well developed, armed buccal capsule and two or three rows of spines 

 down the body. 



Its suggested systematic position would, therefore, be 



Superfamily Spiruroidea Railliet and Henry, 1915. 

 Family Aeuariidae Seurat, 1913. 



Subfamily Physalopterinae Seurat, 1913. 

 Genus Rictularia Froelich, 1802. 



Literature. 



Dujardin, F., 1845. — Histoire naturelle des helminthes ou vers intestinaux. Paris 



(Gnathostoma, p. 287; Bictularia, pp. 280-281). 

 Hall, M. C, 1914. — A new nematode, Bictularia splendida, from the coyote, 



with notes on other coyote parasites. Proc. U.S. Nat. Mus., 



46, No. 2012, pp. 73-84, 6 figs. 

 , 1916.— Nematode parasites of mammals of the orders Rodentia, Lago- 



morpha, and Hyracoidea. Proc. U.S. Nat. Mus., 50, No. 2131. 



(Rictularia, pp. 168-175). 

 Irwin-Smith, V., 1921.— Notes on Nematodes of the genus Physaloptera, with 



special reference to those parasitic in reptiles. These Proceed- 

 ings, xlvi., pp. 492-502. 

 JAGERSKIOLD, L. A., 1909.— Nematoden aus Agypten und dem Sudan. Rictularia 



und Dichelyne. Results Swedish Zool. Exped. Egypt and the 



White Nile, 1901, pt. 3, 25, pp. 1-66, 4 Pis., 23 test-figs. 

 Johnston, T. H., 1912.— Internal Parasites Recorded from Australian Birds. 



The Emu, xii., 2, pp. 105-112. 

 , 1912b. — A census of the Australian reptilian Entozoa. Proc. Roy. 



Soc. Queensland, sxiii., pp. 234-249. 

 ^ 1916. — A census of the Endoparasites recorded as occurring in 



Queensland, arranged 'under their hosts. Proc. Roy. Soc. 



Q'land, xxviii., pp. 31-79. (Reptilia, pp. 56-59). 

 Seurat, L. G., 1915.— Sur les Rictulaires des Carnivores du Nord-afrieain et les 



affinites du genre Rictularia. Comp. Rend. Soc. Biol, 78, No. 



11, pp. 318-322, 3 text-figs. 



