— 137 — 



transversely striated forming a series of rings divided from 

 each otlier by a fairly deep groove. The widtli of these rings 

 reaches 0,04 — 0,07 mm. The anterior ring is provided with 

 6 small papiliiform lips . surrounding the mouth-opening. 

 The latter leads into a very elongated and narrow oesopha- 

 gus provided Avith a bulb in its posterior part. The entire 

 length of the oesophagus reaches 1,7 mm., Avhich makes ^U — V2 

 of the entire body-length. The width of the elongated 

 part of the oesophagus reaches only 0,085 mm. The bulb, 

 0,255 long and 0,3 mm. wide, provided with a chitinous mas- 

 ticating apparatus protrudes with its posterior part into the 

 cavity of the intestine, forming the so called „ventriculus". 

 The intestine, wdiich is of equal width throughout, terminates 

 by the anus at a distance of 0,34 mm. from the caudal end. 

 The latter is provided with a small pointed appendix the 

 length of which reaches 0,15 mm. The width of the body 

 varies in different parts: in the region of the end of oeso- 

 phagus it is 0,65 mm., in the region of the genital aperture — 

 0,75 — 0,8 mm., on the level of the anus— 0,42 mm. 



The genital aperture is situated somewhat behind the mid- 

 dle of the body-length, at a distance of 2,9 mm. from the 

 cephalic end, dividing the anterior and posterior parts of the 

 body in the ratio 19:17. The ripe eggs are found exclusively 

 in the posterior half of the body, there being none ante- 

 riorly to the genital aperture. The form of the eggs is very 

 peculiar: they are of a trilateral form with a lid on one of 

 the poles. The sides of the shell are parallely striated, the 

 surface of the shell is of a finely granulated character. The 

 length of the eggs is 0,096 — 0,105 mm. at a width of 0,06 mm., 

 and height— 0,048 mm. 



Notwithstanding some disagreement which exists between 

 the abovenamed measurements and those of Linstow, 

 I still refer this parasite to the species Oxyiiris annulata 

 Linst. 1899. The reason for this is the following: Linstow 

 speaks of the cuticle being deeply striated transversely, the 

 width of the rings being 0,079 mm., of the presence of 

 6 minute papillae on the head, of a long oesophagus compo- 

 sing V4 — V5 part of the entire body-length, of a short poin- 

 ted tail, of the vagina opening in the posterior half of the 

 body and dividing the latter in the ratio 13 : 10. The females 

 of Linstow's specimens reached 5,57 mm. in length and 



