502 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



PLATK XX. 



Mrt<i>Hitri>lu>xin <//' Alphens heterochelis from Beaufort, North Carolina, drawn from nature by W. K. 



Brooks. 



FIG. 1. Embryo just before hatching. 



FIG. 2. View of a larva \vhich was captured in the tow net at Old Topsail Inlet, North Carolina, 

 June 25, 1883. It is about eighteen one-hundredths of an inch long, and is a little 

 younger than the one shown in PI. xvii, Fig. 3, and a little older than that shown in 

 Fig. 3 of this plate. 



FIG. 3. Ventral view of a larva little younger than Fig. 2. 



FIG. 4. TeLson and swimming appendages of the larva shown in Fig. 3. 



Fid. 5 First maxilla of the same larva. 



FIG. (i. Second maxilla of the same larva. 



FIG. 7. First maxilliped of the same larva. 



FIG. 8. Second maxilliped of the same larva. 



FIG. 9. Third maxilliped of the same larva. 



