SEA-EISIIEltlES LABORATORY. 491 



Plate I. 



Fig. 1. Cancer payurus, from above. Small specimen. 



Fig. 2. C. pagurus, female, from below. Only the 

 stumps of the pereiopods are shown. This 

 figure shows the shape of the abdomen, and 

 also the " pleural groove." x i. 



Fig. 3. C. pagurus, male, from below. Only the 



stumps of the pereiopods are shown, 



Fig. 



4. 



Fig. 



5. 



Fig. 



U. 



Fig. 



7. 



Fig. 



8. 



Fig. 



9. 



Fig. 



10. 



Fig. 



11. 



Fig. 



12. 



Fig. 



13. 



Fig. 



14. 



Fig. 



15. 



Fig. 



16. 



Fig. 



IT. 



Plate II. 



First antenna (antennule) of right side, seen 

 from below. x 2. 

 Eight second antenna, from below. x 2. 



Eight mandible, from below. The apophysis 

 is also shown with the tendons of the external 

 adductor, the internal adductor and the 

 external abductor muscles. x 1. 



Eight first maxilla, from below. x 1. 



Eight second maxilla and scaphognathite, from 

 below. x 1. 



Eight first maxillipede, from below. x 1. 



Eight second maxillipede, with podobranch, 

 from below. x 1. 



Eight third maxillipede, with podobranch, 

 from below. x 1. 



Anterior view of the right chela (first pereio- 

 pod). x 1. 



Anterior view of the right third walking leg 

 (fourth pereiopod). x 1. 



First abdominal appendage of male of right 

 side, x 1. 



Second abdominal appendage of male of right 

 side. x 1. 



First and second abdominal appendage of male, 

 viewed from left side. x 1. 



Anterior view of a right abdominal appendage 

 of female. x 1. 



