266 BULLETIN OF THE 



Fig. 5. First 2oea-stage. 



Fig. 6. The same, viewed from below : a, labrum ; h, process of the carapace ex- 

 tending forward under the eyes ; c, mandible ; d, metastoma ; c, first 

 maxilla ; /, outer branch of firet maxilliped ; g, inner branch of first 

 maxilliped ; h, outer branch of second maxilliped ; i, inner branch of 

 second maxilliped ; k, anus ; I, telson. 



Eye-stalk and eye of the same stage. 



First antenna of the same : a, rudiment of the secondary flagellum ? 



Second antenna of the same : a, b, dentiform processes ; c, rudiment of 

 the future flagellum. 



Mandible. 



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



Second maxilla : a, inner lobe ; h, scaphognathite. 



Posterior border of the telson (^ in. obj.). The arrow indicates the median 

 line of the telson. 



A spine and two adjacent denticles of the same, more highly magnified (^^ 

 in. obj.). 



Posterior part of the carapace, viewed from behind and below : a, thick- 

 ening of the integument at the point where the lateral spines appear in 

 later stages of the zoea ; h, abdominal sinus. 



PLATE II. Porcellana (Polyonyx) macrochelea. 



Last zoea-stagc. 



Fig. 1. Lateral view of the zoea. 

 Fig. 2. Posterior portion of the carapace from below. 

 Fig. 3. Cross-section of the rostram. 



Fig. 4. Cross-section of one of the posterior horns of the carapace. 

 Fig. 5. Telson : a, the antecedent abdominal segment ; b, the sixth abdominal 

 segment of the next stage, showing through the integument of the zoea ; 



c, d, e, the inner and outer branches of the last abdominal appendages 

 and the telson of the next stage showing through the telson of the 

 zoea. 



Fig. 6. First antenna : a, swelling at the base for the lodgment of the auditory 

 organ ; b, inner branch ; c, outer branch ; d, sensoiy hairs on the outer 

 branch. 



Fig. 7. Second antenna : a, internal branch (the annuli of the flagellum of the 

 antenna of the next stage are seen within) ; b, external branch ; c, out- 

 let of the " green gland." 



Fig. 8. Mandil)le : a, rudiment of the palpus. 



Fig. 9. Metastoma. 



Fig. 10. First maxilla : a, inner lobe ; b, outer lobe ; c, palpus. 



Fig. 11. Second maxilla : a, scaj)hognathite. 



Fig. 12. Third maxilliped : a, internal branch ; 6, external branch. 



Fig. 13. The five following pairs of appendages (Decapodal legs) as they appear 

 when removed from under the cara])ace of the zoea : a, cheliped ; b, c, 



d, e, ambulatory pairs ; /, gilb. The chclai uf the first and fifth pairs 



