EXPLANATION OF PLATE IV. 



FIGURE 14. Orchestia agilis Smith, (p. 555;) male; lateral view, enlarged five di 

 ameters. 



15. Gammarus ornatus Edwards, (p. 557;) male; lateral view, enlarged two 

 diameters. 



16. Amphithoe maculata Stimpson, (p. 563 ;) male ; lateral view, enlarged 

 two diameters. 



17. Ampelisca sp., (p. 561 ;) lateral view, enlarged five diameters. 



18. Cerapus rubricornis Stimpson, (p. 565 ;) female ; lateral view, enlarged 

 five diameters; and hand of th e second pair of legs of the male, en 

 larged the same amount. 



19. Unciola irrorata Say, (p. 567;) male; dorsal view, enlarged six diameters. 



(All ttie figures were drawn by J. H. Emerton and S. I. Smith.) 



