Fig. 6. The same 



Fig. 7. The same 



Fig. 8. The same 



Fig. 9. The same 



Fig. 10, The same 



Fi". 11. The same 



MUSEUM OF COMPARATIVE ZOOLOGY. 329 



Plate III. 



Fig. 1. Fourth larval stage ; cephalo- thorax, from below. 



Fig. 2. The same ; penultimate thoracic appendage. 



Fig. 3. The same ; last thoracic appendage. 



Fig. 4. Fifth larval stage ; cephalo-tliorax viewed from below, sp, .spinous 



process of second pair of antenna). 

 Fis. 5. The same ; anterior part of the carapace. 



fifth abdominal somite, viewed from the side. 



labrum (/ b) and mandibles (III). 



second maxilla. 



natatory branch of the tenth pair of appendages. 



abdominal appendage of the first pair. 



abdominal appendage of the second pair (those of the 

 third and fourth pairs have the same form). 

 Fig. 12. The same ; abdominal appendage of the fifth pair. 

 Fig. 13. The same ; telson and swimmerets. 

 Fig. 14. Sixth larval stage, one moult after the fifth larval stage ; antenna of 



the second pair; sp, spinous process. 

 Fig. 15. The same ; first cheliped. 

 Fig. 16. The same ; second cheliped. 

 Fig. 17. The same ; one of the abdominal appendages. 

 Fig. 18. The same ; telson and swimmerets. 



Plate IV. 



[Note. Figs. 9-14 are from drawings by Mr. A. Agassiz.] 

 Sixth larval stage, two moults after the fifth larval stage, lateral view. 

 The same ; second antenna ; s p, spinous process. 

 The same ; cheliped with its external, natatory branch (r e). 

 The same ; first abdominal appendage. 

 The same ; second abdominal appendage. 

 The same ; posterior margin of the telson. 

 Sixth larval stage, three moults after the fifth larval stage ; anterior 



end of fii-st antenna. 

 The same ; telson and swimmeret. 

 Seventh larval stage ; rostrum and eye. 

 The same ; second maxilliped. 

 The same ; third maxilliped. 

 The same ; chela. 



The same ; rudimentary external branch (re) of thoracic legs. 

 The same ; posterior thoracic leg. 

 Young prawn, 8 mm. long, which has acquired most of the characters 



of the adult. 

 Adult ; third maxilliped. 

 The same ; scale of second antenna. 



