NOTES ON NEMATODES OF THE GENUS PHJSALOPTEBA. 



Part iii. The P'hysaloptera op Australian Lizards. 



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



Zoology. 



(Thirty-eight Text-figures.) 



[Read 28th June, 1922.] 



Three collections of Physaloptera material, received from the Zoology De- 

 partment of the University of Sydney, contain specimens of a species which ap- 

 pears to be identical with Physaloptera antarctiea Linstow. Linstow's description 

 is insuflScient to characterise the species clearly, but the few measurements which 

 he gives accord with those of specimens which are regarded in the following 

 paper as representing the typical variety. 



Two of the collections (B and C) consist entirely of this variety (var. 

 typica) ; the third (A) contains a few specimens of the same variety, mostly 

 immature, scattered among a large number of very similar worms, which show 

 certain constant differences and have been considered as a new variety of the 

 species, var. lata. 



All three collections were obtained during class dissection of lizards, lot A 

 being labelled "From the intestine of a lizard, 1915," lot B "From the lower 

 intestine of a blue tongued lizard, Tiliqua scincoides, 24 June, 1919," lot C 

 "From the intestine of Tiliqua scincoides, 12 August, 1919." In each case the 

 Physaloptera were the only Nematode parasites present, and occuiTed in con- 

 siderable numbers, lot A consisting of about 65 specimens, among them many 

 lai-vae and 21 adult males, lot B of some 50 larvae and adults, 20 of them males, 

 lot C of 29 specimens, 17 of them males. 



Treatment. — The specimens in lot B were received alive, in normal salt 

 solution, and a few of them were kept in this medium for periods ranging up 

 to three weeks, when they were still alive, though very sluggish. The remainder 

 were killed at once, various fixatives being tried for comparison. Hot corrosive 

 sublimate acetic proved a very bad fixative. Specimens immersed in this for ten 

 minutes and afterwards treated with 70% alcohol and iodised alcohol, were so 

 hard and shrunken as to be almost useless for examination. Carl's solution was 

 also unsatisfactory, and fixation in warm glycerine-alcohol did not secure well 



