476 MEMOIRS OF TBE I^JATIONAL ACADEMY OF SCIENCES. 



Plate VII. 



FiGr. 10. Left secoud maxilla of larva at the point of liatching, before the tirst molt, x 276. Com- 

 pare with Figs. 25 anil 21. 



Fict. 11. First swimming larva, after the first molt, .seen from below. Pigment cells, brown. 

 L=,JjJ\, in. (measured from tip of rostrum to median notch of telson). Length of 

 rostruDi = jfo in- X 70. 



Fig. 12. Right first maxilla of first larva, seen from the outer side. Setse rudimentary. Compare 

 Figs. 19, 25. x276. 



Fig. 13. Telson of larva before first molt, seen from below. Compare Fig. 11. The setre are 

 invaginated and covered with a loose cuticle. x276. 



Fig. 14. Right first maxilliped of larva on the point of hatching, seen from the outer side. Setfe 

 invaginated. Compare Figs. 22, 25. x27G. 



Fig. 15. Labrum and right mandible of larva, seen from above. x276. 



Fig. 16. Right third maxilliped of larva on the point of hatching, seen from the outer side. Com- 

 pare Fig. 25. x276. 



REFERENCE LETTERS. 



a, ontermoBt spine in telson of larva at the point of hatching. 

 d, equivalent of a in first locomotory larva. 

 Lh, labrum. 



