NEMATODE GENUS PHYSALOPTERA. 1063 



row of small denticles on the inner surface parallel to the edge 

 of the lip. 



The muscular part of the oesophagus is thinner than the 

 glandular part, and is encircled by the nerve ring at its base. 

 The whole organ is short, and forms in the females l/7th and in 

 the males nearly l/8th of the total body-length. 



Fevude. 



The vulva opens practically flush with the surface, there 

 being only a slight trace of an elevation. Its position is 

 post-oesophageal, and divides the body in the ratio of 1 : 2*4 ; it 

 leads into a long and thick-walled vagina about 2 mm. long 

 by 100 /x broad ; its most anterior portion is slightly twisted. 

 The following egg-chamber is straight, and lies parallel to the 

 intestine ; it is slightly thicker than the vagina but shorter, 

 measuring 1*2 mm. long by 133 /x broad. The following common 

 trunk is relatively short, and is thinner than the vagina ; it is 

 570 jx long and 57 /x thick. From its posterior end the four uteri 

 take their origin at the same level, but their cavities arise by a 

 double subdivision of the unpaired duct. The uteri at first pass 

 forwards to beyond the posterior end of the oesophagus, after 

 which they bend backwards and fill the body almost to the 

 posterior end. 



The eggs are thick- walled, oval, and fully embryonated in utero : 

 they measure 50 /x long by 35 /x, broad'. 



The body is terminated by a relatively long and pointed tail, 

 forming l/47th of the total length; its caudal pores are situated 

 just behind its middle. 



Male. 



The caudal bursa is large and provided with well-developed 

 al?e ; its ventral surface is traversed by coarse cuticular eleva- 

 tions arranged in longitudinal rows. The anus is a large and 

 transversely oval aperture, with a thickened rim, very prominent 

 when viewed from the ventral surface ; it is situated about 850 /x 

 from the tip of the tail. 



The four pairs of pedunculated papillee are equidistant from 

 each other ; two pairs are pre-anal and two pairs are post-anal 

 in position ; of the three pre-anal ventral papillfe the median one 

 is situated slightly closer to the anus tha,n the other two. Behind 

 the anus there ai-e five pairs of sessile papillae; the 1st and 

 2i.id pairs of these are small, and situated close together just 

 behind the anus, one pair behind the other ; the 3rd and 4th 

 pairs are closely approximated, and found just in front of the 

 middle of the tail ; while the last pair is situated just postei'ior to 

 the front margin of the posterior quarter of the tail. 



The spicules are very unequal, and appear to vary in size; but 

 these variations may be due to the difiiculty found in measuring 

 them. The right spicule is short, and varies from 185 to 240 /i 



71* 



