BY VERA IRWIK-SMITH. 427 



not attenuated in the posterior half, as it is in the encysted larvae, and it is 

 altogether stouter and more opaque. The oesophag-us is also somewhat thicker 

 and the denticular formation is quite different. 



Only one other record exists of a Physaloptera from any species of Lygosoma. 

 This was listed by Dr. T. H. Johnston as Physaloptera sp., from Lygosoma 

 {Hinidia) tenue, duodenum, Millfield, N..S.W. The record is not accompanied by 

 a description, so that it is impossible to compare Dr. Johnston's specimen with 

 these encysted larvae. 



Collections of internal parasites were made by Dr. Cleland from three 

 species, Lygosoma {Liolepisma) entrecasteauxii, Lygosoma (Hiimlia) taeniolatum, 

 and Lygosoma (Hemiergis) descresiense, and Dr. Johnston's lists contain single 

 records from three species, but, with the exception of the specimens already 

 noted, none of these relate to Physaloptera. 



There is no indication that nematode cysts have ever before been observed 

 in this or any other Australian lizard genus, but, apparently, very few examples 

 have been searched, and it is possible that when lizards are examined in much 

 greater numbers, Physaloptera larvae in an encysted condition will be found to 

 be not uncommon. 



Note {added 30th September, 1922). — Since the above was written, Mr. 

 Maekerras has found a solitary cyst of the same character, embedded subperi- 

 toneally on the stomach-wall of another example of Lygosoma {Hinulia) taenio- 

 latum. The cyst contained a single specimen of a Physaloptera larva exactly 

 similar to those described here. It was removed from the cyst while still alive, 

 and fixed in hot 70% alcohol in weU extended condition. It is a large, well- 

 preserved specimen, a little over 12 mm. long. No other cysts, nor any free 

 nematodes were found in this host-specimen, although a thorough search was 

 made. 



List of lizard-hosts referred to in Parts 3 and 4 of Physaloptera notes, with 

 the helminth parasites recorded from- them. 



Gym-nodactylus platurus Shaw Physaloptera bancrofti Irwin-Smith, 



Pharyngodon sp. 



Lialis burtonii Gray Physaloptera sp. (larvae). 



Lygosoma (Hinulia) taeniolatum White Physaloptera sp. (encysted larvae). 



Lygosoma (Liolepisma) entreeasteau.vii Oxyuris sp., Physaloptera sp., Eictidaria 

 disparilis Irwin-Smith. 



Tiliqua occipitalis Gray Physaloptera antarctica Linstow. 



Tiliqua scincoides White Physaloptera antarctica var. typica Lin- 



stow, and var. lata Irwin-Smith. 



Varanus varius Physaloptera .antarctica var. typica Lin- 



stow, Physaloptera clelandi Irwin- 

 Smith, Filaria sp., Echinorhynchus 

 sp., P. tidswelli (Cestode). 

 In conclusion, I wish to make gTateful acknowledgment of the assistance 



received in the preparation of this series of Physaloptera studies: to Miss Chase 



and students of the Zoology Dept. of the University of Sydney, Professor J. B. 



Cleland, Miss M. J. Bancroft, and Mr. I. M. Maekerras for providing the material, 



to Dr. J. R. Dixon for the preparation of sections, and to Mr. J. R. Kinghorn. 



of the Australian Museum, for supplying me with information relating to the 



liosts and for the selection of the proper host-names. 



