266 



ZOOLOGY 



the sixth and last thoracic, n It bears a pair of appendages 

 which are reduced to a small valve-like structure overlying 

 the sexual aperture. In the female this last thoracic segment 

 is fused with the first abdominal. The four abdominal seg- 



Fia. 158.— Dorsal view of male Cyclops. The 

 reproductive organs are di^ammatio. 

 After Hartog. 



1. Antennae. 



2. Carapace. 



3. Testis. 



4. Vas deferens. 



5. Vesicula seminalis. 



6. Bye. 



ments are cylindrical] in shape, and are entirely devoid of 

 appendages ; the last, however, bears the caudal fork. 



The mouth leads into a narrow gullet which ends in the 

 anterior end of the stomach, an oval sac extending back to 

 about the second thoracic segment. The chitinous cuticle 



