426 NE3IAT0DES OP THE GENUS PHYS-iLOPTEEA, iv., 



The cysts vary in diameter from 1 to 2.34 mm., and contain from one to seven 

 worms, which can be removed without difficulty by cutting round the circum- 

 ference, and turning the wall back. When more than one is present, the worms 

 are closely intertwined, in a ball-like mass, but, with a little care, they can he 

 , separated whole and extended in good condition for microscopic examination 

 (Text-fig. 35). 



Their large size is somewhat remarkable. The largest of them attain a length 

 of nearly 12 mm. and a maximum diameter of .4 mm., but none of them show 

 any trace of genitalia. Of fifteen larvae, taken from four cysts, the average 

 length is 7.4 mm., four in one cyst measuring from 6.4 to 7.6 mm., and seven in 

 another from 6.0 to 8.0 mm. A difference in the leng-th and shape of the tail 

 evidently distinguishes the two sexes, the female tail being short, fairly thick and 

 blunt, the male tail longer, thinner, and sharply pointed. Two of each form were 

 found in one cyst containing four larvae. 



Examination and measurements of the larvae were made both in glycerine 

 and alcoholic phenol. 



Description. — Physaloptera larvae. Genitalia not developed. Fairly stout 

 bodied, tapering posteriorly, but not greatly attenuated anteriorly; anterior half 

 of body broader than posterior half; tail one-fortieth to one-thirtieth of body- 

 length, longer, narrower and more sharply pointed in the male than in the 

 female, the average leng-ths in the two sexes being 240 and 176 fx ( Text-figs. 37, 

 38). Cuticle clear and delicate, body very transparent, oesophagiis very heavy 

 and dark in contrast; transverse striation very fine. Cephalic collarette and alae 

 well developed. Labial papillae large; external median tooth truncated at tip, 

 and slightly notched; only one lateral tooth on each side, slender, needle-like; no 

 internal denticular border (Text-fig. 34). Muscular oesophagus about one- 

 seventh to one-eighth of total length of oesophag-us, narrower and clearer than 

 glandular oesophagus, a well marked line dividing the two. The anterior part 

 of muscular oesophagus distinctly different in structure from the posterior part. 

 Nerve-ring surrounding it very close to the junction with glandular oesophagus. 

 Post-cervical papillae about 80 ^u, behind the junction (Text-fig. 33). Short, dark, 

 granular bodies on each side of the oesophagus, anteriorly, not reaching to' the 

 level of the nerve-ring, apparently cervical glands. Total length of oesophagus 

 one-fourth to one-fifth of body-lengfh in the smaller larvae, slightly less in the 

 larger specimens. Base of oesophag-us inserted well into lumen of intestine 

 (Text-fig. 36). Intestine narrow, thin-walled, delicate. 



Measurements of one example. — Total length, 7.6 mm.; maximum diameter, 

 256 IX ; diameter at base of collarette, 148 ^ ; at anus, 112 ^. Tail, 240 ^. Distance 

 from cephalic extremity of nerve-ring, 203 ;i; post-cervical papillae, 333 |U,- Length 

 of buccal cavity, 37 /x, ; of muscular oesophag-us 208 fx ; total length of oesophagus, 

 1.63 mm. Width of muscular oesophagus, 62^; of glandular oesophagus, 129 ;«,. 



Host. — Lygosoma {Einulia) taeniolatum White. Location. — Body cavity. 

 Locality. — "Castle Rock," Middle Harbour, Sydney. 



Collected by Miss Bancroft and Mr. Mackerr'as, 14/9/21. 



The host formed one of three examples of this species examined at the ^ame 

 time, by Miss Bancroft and Mr. Mackerras for internal parasites. No nematodes 

 were found in the others. 



These encysted larvae are clearly distinct from the Physaloptera sp., described 

 above, from Lygosoma entrecasteauxii. The absence of genitalia in encysted 

 specimens much larger than that specimen, in which the female genital system 

 is well developed, shows that they belong to a much larger species. In addition, 

 the sliape of the body is different. In the specimen from L. entrecasteauxii it is 



