424 NEMATODES OP THE GENUS PHYSALOPTERA^ iv., 



Distance from posterior extremity of most posterior loop' of uterus, 780 yu,; of 

 ovaries, 416^. Maximum width of uterus, 33 yu. Vestibule, 960 x 52^; reser- 

 voir, 800 X 208 yn; common tnink, 256 x 48 /a. Distance between first and second 

 bifurcation, 256 ,«,. Muscular oesophagus, 176 (?) x 112 ^x; total length of 

 oesophagus, 1.70 mm. ; width at its base, 176 fi. 



Host. — Lygosoma (Liolepisma) entrecasteauxii. Location. — Alimentary 



canal. Locality. — Flinders Island, Bass Straits. 



CoUeeted by Dr. J. B. Cleland, 25/11/12. 



Two specimens of this host species were examined. The second specimen 

 contained only Oxyuriidae. 



Except for the larger size and the development of genitalia, there is little, 

 in the general conformation and proportions of this specimen, to distinguish it 

 from the larval Physaloptera found in Lialis burtonii and described above. They 

 may all belong to the one species, but this can not be determined, nor the species 

 clearly chai-aeterised, until more specimens are available for examination. It is 

 apparently a young specimen, not fully grown. 



From an examination of numerous examples of P. antarctica, it has been 

 shown (Irwin-Smith, These Proc, 47, 1922, p. 237) that measurements taken 

 from a single specimen are, alone, of little specific value, since considerable 

 variations, both in the proportions and conformation of organs, are found to 

 occur within a single species. In view of this, and of the immaturity of the 

 single female specimen found, and of the absence of males, it is not desirable, at 

 present, to propose a new species for this specimen, though it is evidently dis- 

 tinct from any of the species with four uteri hitherto described. 



In none of the other species is the female genital system well developed in 

 specimens of such a small size. The dichotomous division of the very short 

 common trunk into four uteri, with the first two branches equal in length to the 

 common trunk is also distinctive, if it is a constant feature. It is of heavier 

 build than examples of P. antarctica and P. bancrofti of the same size, and the 

 denticular formation is different. 



Although so much smaller in size, its heavy build recalls that of P. clelandi; 

 but the tail is relatively longer and more slender and sharply pointed, and the 

 oesophagus is shorter in proportion to the length of the body. Marked dif- 

 ferences from P. pallaryi, P. varani, and P. abbreviata, in addition to the size 

 and relative proportions of the body, are the situation of the vulva behind the 

 termination of the oesophagus instead of in front of it, where it is found in P. 

 pallaryi, the dichotomous instead of direct division of the common trunk, as in 

 P. varani, and the denticular formation with a large inner double-pointed tooth, 

 unlike P. abbreviata and the other two species. 



Encysted Physaloptera larvae in Himdia taeniolatuin. 



From Mr. Mackerras I have received, recejfitly, a portion of the stomach- 

 wall of an Hinulia taetiiolatum infested with nematode cysts, with the information 

 that similar cysts were numerous in the mesentery and behind the peritoneum on 

 the posterior body wall. 



The cysts contain larvae which are undoubtedly Physaloptera, and the evi- 

 dence they supply of migratory and cyst-forming habits in this genus of nema- 

 todes is of great interest and significance. 



The portion of the stomach-wall preserved was entirely covered with them, 

 forty-two occupying an area one centimetre square (Text-fig. 30). Beyond this 

 area they were more scattered, but were fairly thick all over the stomach. It 

 was not possible to determine, from a macroscopic examination of the fragment 



