Davaineid Oestode from a Wallahij. GOT 



tnmk is situated about midway between tlic veutral excre- 

 tory vessel and the inner margin of the cirrus-poucli ; it 

 may, however, approach and lie close to the excretory vessel. 

 On the aporal side the nerve-trunk lies in close proximity 

 to the ventral excretory vessel. The course of the nerves in 

 the head region was not followed. 



(d; Genital Organs (tigs. 3 and -i). — Each mature seg- 

 ment possesses one comi)lete set of male and female genitalia, 

 with their genital pores close together and unilateral in 

 position. 



These pores are in the anterior third of the segment, and 

 are situated on a slight eminence. Each eminence is over- 

 hung by the projecting posterior angle of the segment 

 preceding. 



The genital rudiments of the ovaries are the first to appear 



Tier. 4. 



Mature sej^ments, slightly flattened. 

 (Magnification about 40.) 



iV. = nerve-cord ; Oy. = ovary; 5^.6^. = shell-gland; 7". = testes; V.D.= 

 ras deferens; F.-£^. C'. = ventral excretory gland; JT. 6-'.= yolk- 

 gland. 



about 8 mm. from the anterior end ; some mms. further 

 down the vagina begins to develop, to be soon followed by 

 the vas deferens. The rudiments of the testes appear very 

 much later, their first indications being at about 40 mm. 

 from the anterior end. Mature segments are found about 

 n mm. further down. 



All the genitalia are confined to the central third of the 

 parenchyma, being bound dorsally and ventrally by the thin 

 sheet of transverse muscles and laterally by the ventral 

 excretory canals. 



The male organs consist of about 50 rounded testes, about 

 65 /x in diameter, arranged in two groups separated by the 

 ovary. The larger group, which consists of about three- 

 fourths of the number of testes, is situated aporally. The 

 testes do not pass laterally over the ventral excretory canal. 



