NEMATODE GENUS PHYSALOPTERA. 



1053 



The cesophagus is straight and immediately follows the lips; it 

 thickens very slightly towai-ds the posterior end. Its anterior 

 1/1 0th, which is slightly thinner than the rest, forms its glandular 

 part, and the nerve ring encircles it in its posterior third. The 

 entire organ forms l/6'4 in the male, and 1/6-2 in the female, 

 of the total body-length. 



Female. 



The females are large and stout ; they vary in length from 41 

 to 100 mm., with a thickness of 1-8 to 2'8 mm. in their posterior 

 third. The anterior two-thii'ds taper gradually towards the 

 cephalic extremity ; tlie postei'ior l/8th tapers to end in a short 

 and conical tail l/70th to l/90th of the body-length ; the caudal 

 pores are situated in its posterior half. 



The vulva is situated on a slight elevation behind the hind 

 end of the oesophagus : its position divides the body into the 

 ratio of 1:5. The general characters of the female genitalia are 

 exactly similar to those described for Ph. varani, except that 

 the common trunk poi-tion behind the egg-chamber is relatively 



Text-figure 27. 



Fhysaloptera mordens Leiper. 

 A = Ventral view of lips. B = Inner view of lip. 



larger. The four uteri are twisted about each other in a com- 

 plicated way, or fill practically the whole of the body as far as its 

 posterior eighth. 



The eggs are ova,l and thick-shelled, and vary from 45 to 49 /x 

 long by 32 to 34 /x, broad. They are fully embryonated when laid. 



Male. 



The males vary in length from 29 to 34 mm., with a thickness 

 of '9 to 1 mm. in their posterior quarter; the body is slightly 

 attenuated anteriorly. 



The bursa is long and pointed, and is reflexed ventralwards. 

 Its under surface is ornamented with small triangular spike-like 

 processes arranged longitudinall}^, and extending as far as the 

 4th pair of post-anal ventral papillte. The four pairs of stalked 

 papillse are arranged in two groups, the anterior two pairs being 

 pre-anal and the posterior two pairs post-anal in position ; the 

 1st and last pairs are shorter than the other two, and their origins 

 are slightly more ventral. 



The three pre-anal ventral papillfe are of equal size, and are 



