some Parasitic Nematodes 499 



tlian tlie posterior; and in arldition to these there appears to 

 be a subdorsal |)air at the extremity of the tail. There are 

 at least thirty-throe pairs of preanal papilhe, arranged in a 

 close series on either side of the ventral surface. These have 

 rounded o|ranular pulps, and are easily nbsMved. 



In the female the tail measures about 0'5 mm. in lenfi;th. 

 The vulva is situated at, roughly, the anterior third of the 

 body — at 50 mm. from the anterior end in a specimen 155 mm. 

 long, and at 30 mm. in a specimen 113 mm. long. The 

 vagina, in the 113 mm. s])ecimen, runs forward for about 

 6 nitn,, then bends sharply back upon itself and widens 

 ra|)i(lly into the unpaired portion of the uterus. This runs 

 back for a distance of about 12»mm. from the bend before 

 giving off the two uterine branches. Each of these, just 

 before its junction with the unpaired portion, has a slight 

 spindle-shaped swelling. The branches of the uterus merely 

 follow a somewhat sinuous course for the greater part of their 

 length, but posteriorly they form one or two anteriorly-directed 

 loops. They pass into the oviducts at about 26 mm. from 

 the posterior end of the worm. The ovarian tubes are slender 

 and greatly convoluted, their coils extending posteriorly 

 almost to the extremity of the body, and anteriorly to within 

 22 mm. of the head-end. Their terminal portions are 

 posterior. 



The eggs are roundish-oval, with a thick sliell having a 

 granular surface-pattern and measuring 0"07-0'875 x 065- 

 0*07 mm. ]\lany of them contain a fully-formed embryo, 

 but others taken from the unpaired portion of the uterus 

 show only segmentation-stages. 



III. — Note on Two Species of Porrocjsclm from Bihds 



[P. ensicaiidatum (Zeder, 1 bOO) and P. semiteres (Zedei', 



I.SOO)]. 



In a previous paper [Raylis (1920)] the writer gave a 

 provisional list of species to be assigned to this genus, and 

 indicated P. ensicandutum and P. semiteres as distinct forms. 

 The material available for the study of P. semiteres was very 

 scanty at the time ; but an op[)ortunify having recently 

 occurred, through the kindness of my friend Capt. li. 

 Daubney, of exannning new and well-preserved specimens 

 from VaiuUus ranelluK, it seems desirable to give a brief note 

 on the species. 'iM.o opportunity has also been taken of 

 comparing it with P. ensicaiidatum, since there has been 

 some doubt as to whether the two forms were not identical. 



