No. 5-] MALE ERPETOCYPRIS BARBATUS FORBES. 20I 



between the two male max- 

 illae. The structure of the 

 legs is practically the same 

 in both male and female. 

 The same may be said of the 

 abdominal rami, although 

 those of the male are a trifle 

 longer and more sinuous 

 than those of the female. 



The copulatory organs, 

 the structure of which is 



depicted in Fig. 3, are quite large, and, as usual in male Ostra- 

 cods, of unequal size. The following table contains the dimen- 

 sions of the copulatory organs of five different individuals. 



Fig. 3. 



It will be seen at a glance that the ratio of the width to 

 the length is much greater for the smaller than for the larger 

 organ of the same individual. 



The vas deferens, shortly after enter- 

 ing the proximal end of the copulatory 

 organ, forms an irregular enlargement 

 (Fig. 3, E). After leaving the small dis- 

 tal end of this portion, the vas deferens 

 coils into a loose knot before terminat- 

 ing, near the middle of the organ, in two 

 or three tubes. 



Zenker's organ (Fig. 4, A) is about 

 nine times as long as wide, being 0.81 mm. long and 0.09 mm. 

 wide. Its structure is simpler than the corresponding organ of 

 any other Ostracod known to ine. The central core is com- 

 posed of a series of narrow rings, arranged one in front of the 



Fig. 4. 



