OF METAxMORPHOSES IN THE CRUSTACEA. 327 



Explanation of the Plate. 



Plate IV. A. 



Fig. 1. Zoea Gigas, Westw. natural size. 

 Fig. 2. Ditto, magnified. 

 Fig. 3. The outer antenna. 

 Fig. 4. The inner antenna. 

 Fig. 5. The labrum. 



Fig. 6. One of the mandibles, a representative of the the palpus. 

 Fig. 7. One of the interior maxillee. 

 Fig. 8. One of the second pair of maxillae. 



Fig. 9. One of the first pair of foot-jaws, developed into a natatory organ. 

 Fig. 10. One of the second pair of foot-jaws, developed into a natatory organ. 

 Fig. 11. One of the third pair of foot-jaws, minute and rudimentaL 

 Fig. 12. View of the underside of the body, as extracted from the cephalothoracic 

 shield. 



a. The first pair of foot-jaws. 



b. The second pair. 



c. The third pair. 



d. The anterior pair of chelate members. 



e. The rudimental branchiae. 



f. The four posterior pairs of simple members. 

 Fig. 13. One of the subabdominal appendages. 

 Fig. 14. The tail, developed. 



Plate IV. B. 



" Eggs and young of a land Crab not undergoing a metamorphosis." — Guilding, MSS. 

 a. The egg. 



Fig. 1. Natural size. 



Fig. 2. Magnified, seen in front. 



Fig. 3. The same, seen in front, having the outer pellicle stripped oflf: the legs 

 on one side extended laterally, the branchiae visible on the other side. 



Fig. 4. The same, seen in front, having the outer pellicle stripped off, seen side- 

 ways. 



Fig. 5. The same, seen in front, having the outer pellicle stripped oflf, seen side- 

 ways, with the limbs and tail extended. 



Fig. 6. The tail. 



Fig. 7. The legs, with the branchiae at the base, not organized. 



MDCCCXXXV. 2 u 



