311 



A NEW NEMATODE PARASITE OF A LIZARD. 



By Vera Irwin Smith, B.Sc, E.L.S., Linnean Macleay Fellow of the Society 

 in Zoology. 



(Seventeen Text-figures.) 



[Read 30th August, 1922.:] 



Two specimens of a nematode, remarkable for the possession of an asym- 

 metrical row of spines down one side, are included in Dr. J. B. Cleland's collec- 

 tion of helminths from Australian reptiles. They were preserved in 70% alcohol, 

 in a phial with one specimen of a Physaloptera sp., and one Oxyurid, all taken 

 from the alimentary tract of a small lizard, the enclosed label bearing the in- 

 scription "Nematodes from lizard (Hinulia) No. 2, alimentary canal. Flinders 

 Is. 25/11/12. Dr. J. B. C." 



In general appearance these worms are very like Physaloptera and, at fii'st, 

 they were taken to be identical with the small Physaloptera sp. found with them. 

 A closer examination revealed the spine row, and proved the distinctive character 

 of the specimens. 



A cuticular ornamentation of spines is rare in reptilian nematodes, and the 

 asymmetrical position of the row in this case gives an added interest and signi- 

 fieanee to the new form. So far as I am aware, nothing of the same kind has 

 been described before. The nearest approach to it is found in the original 

 descriptions of Rictularia cristata Froelich, the type species of a genus which 

 has been recorded only from mammals, and the new nematode has been assigned, 

 provisionally, to this genus, although it does not conform to the generic diagnosis 

 as given by recent writers, Jagerskiold (1909) and Hall (1914). The discre- 

 pancies noted can be discussed better after the description of the new species, 

 when its relationships and systematic position will be considered. 



Unfortunately the only two specimens available are both females, so that 

 the specific characters of the male can not be determined. There is also some 

 doubt about the exact structure of the mouth parts in the two females examined, 

 which are very small and not in good condition. Under the circumstances, it does 

 not seem advisable to propose a new genus for the species at present, though this 

 may be necessary when fuller information is obtainable. 



Rictularia dispaeilis, n.sp. 

 Male unknown. 



Female 7.9 to 8.7 mm. long. Colour whitish when preserved in alcohol, 

 original colour not noted. Body slender, delicate, thickest in the posterior third, 



