NEMATODE GENUS PHYSALOPTERA. 



1031 



Female . 



Mature females vary in length from 25 to 40 mm., Avith a 

 maximum thickness of 850 to 960 yu, ; its greater portion is of 

 more or less uniform thickness, tapering being confined only to 

 the last few millimetres of the two extremities. The tail is 

 obtuse, and forms about l/75th of the body-length. 



The vulva is protuberant, and its position divides the body into 

 the ratio of 1:5. It leads into a slio-htlv coiled vagina 1"6 mm. 

 long by 65 /.i thick. The following egg-chamber is relatively 

 short and thin, being 640 ,«, long and 130 p. in diameter. The 

 common trunk is very short, being only 160/.t long and as thick 

 as the vagina ; its posterior end divides once to give rise to the 

 connections of the two uteri. 



The receptacula seminis are oblong, 240 /.t long and 175 /.t in 

 diameter. 



The eggs are thick-shelled, oval, and embryonated in utero ; 

 they measure 45 by 26 ju. 



Mcde. 



In the males the body is attenuated only in its anterior third ; 

 the longer specimens varied from 18 to 23 mm. long by 710 to 

 770;/ thick. 



Text-fio-ure 13. 



Fhysaloptera monodens Mol. 

 A = Cephalic extremit}', lateral view. 

 B = Cephalic extreuiitj', ventral view. 



The bursa is ovoid, has well-developed alee, and its ventral 

 surface shows longitudinal rows of small irregularly rounded 

 tubercles. The three anterior pairs of stalked papillas are pre-anal 

 in position. Of the three pre-anal ventral papillae the central 

 one is the largest, and is situated closer to anus tha.n the other 

 two. There are five paii's of post-anal ventral papilla?, of Avhich 

 the first two pairs are small and situated in a row immediatelv 

 behind the anus ; the 3rd pair is slightly obliquely placed at 

 about the junction of the 1st and 2nd sixths of the tail; the 

 4th pair is just in front of the middle of the tail. The 

 distance separating the 4th from the 5th pair is slightly less 

 than that between the 3rd and 4th pairs. The caudal pores 



69* 



