268 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 



Fig. 4. First maxilliped of the same : a, inner branch ; b, outer branch. 

 Figs. 5-15. Last stage of the zoea of a Pinnixa, from Newport, R. I. 

 Fig. 5. Anterior view. 

 Fig. 6. Posterior view. 



Fig. 7. Third maxilliped, cheliped, and ambulatory appendages of the future crab, 

 removed from under the carapace of the zoea : a', a", a"', inner, middle, 

 and outer branches of the third -maxilliped ; b, cheliped ; c, d, e, /, am- 

 bulatory appendages ; g, gills. 

 Fig. 8. Third maxilliped : a, inner branch (endognathite) ; b, middle branch (ex- 

 ognathite) ; c, outer branch (epignathite) ; d, gill. 

 Second maxilla : a, scaphognathite. 

 Abdomen : a, b, c, d, first, second, third, and fourth pairs of abdominal 



appendages. 

 Second maxilliped : a, inner branch ; b, outer branch. 

 First maxilliped : a, inner branch ; b, outer branch. 

 First maxilla : a, inner lobe ; b, outer lobe ; c, palpus. 

 a, first antenna ; b, second antenna. 

 Metastoma. 



Note. Figs. 9 and 11 - 15 were drawn from the exuviae of a zoea which had changed into a crab. 



PLATE V. Pinnixa. 



Fig. 1. First crab-stage of a Pinnixa, from Newport, R. I. (developed at one 

 moult from the zoea represented on Plate IV. Figs. 5-15). Dorsal 

 view. 



The same ; ventral view. 



The same ; abdomen viewed from beneath, with its appendages. 



The same ; first antenna. 



The same ; first maxilliped. 



The same ; second maxilliped : a, endognathite ; b, exognathite. 



The same ; third maxilliped : a, endognathite ; b, exognathite ; c, epig- 

 nathite. 

 Fig. 8. Left chela of adult male Pinnixa chcetopterana from Buzzard's Bay. The 

 carapace of this specimen measures 4 mm. in length by 7. 5 mm. in 

 breadth. 

 Fig. 9. Right chela of a small adult female of the same. Carapace, 3 mm. x 

 5.5 mm. 



Fig. 



9. 



Fig. 



10. 



Fig. 



11. 



Fig. 



12. 



Fig. 



13. 



Fig. 



14. 



Fig. 



15. 



Fig. 



2 



Fig. 



3 



Fig. 



4 



Fig. 



5. 



Fig. 



6 



Fig. 



7 



